Pontiac 6x heads on 455. Squatchubs · Registered.

Pontiac 6x heads on 455 061). Jump to Latest ive found some 6x-8 heads somewhat locally for 250 but would need to be gone through and rebuilt. Don't know much about the 96 except they are one of the preferred 455 heads because of the compression ratio. 6X heads came on Pontiac 350-400 from The 670 / 16 type is a pretty good head and around 72cc chamber with screw in studs and 2. 9-1 motor it should be the 6x4's as the 6x8's would make that motor a 7. Time factors/budget limit this project but it is only for summer work transportation(7-8 miles each way). If I were doing what you are doing, I'd search for an 87-90cc head for at least 9:1 CR. Was originally looking for 6X-4s but found these locally at a fair price. Doing so will get you 9. The XE cams are said to make noise because of slapping the valves shut so hard. That's because when the OE pressed in studs get pulled the hole is too big to tap for the correct 7/16" threads (though they can be tapped for 1/2" threads),so your left with two options,niether of which is ideal IMO,option #1 is to heli-coil all 16 rocker bosses for the Find PONTIAC 6. for a 400. The 6X head will give you about 7. I'm sure his will be close to making the Video. to work!Thanks Goatman! The only Aluminum Pontiac D-port Head We are pleased to introduce to you, our aluminum D-port Pontiac head. 4:1 compression Edelbrock p65 dual quad/dual plane intake 2 edelbrock 600 carbs 1 5/8 diameter/unequal length primary headers 2. 5cc already redone Performer RPM intake FiTech EFI RAM AIR exhaust manifolds . or Pontiac heads, 6x any good? Hey guys im new to the forumn here, I own an 01 WS6 that I have quite a bit of work into and now im going to focus on my 68 Firebird 400. First Generation Firebird Forums Tech Help Drivetrain 6X heads from 350 on 455? Forums Calendar Active Threads: Previous Thread #247436 02/29/12 04:52 PM. 060 on intake side & head surface side. 25" stroker, crate motor, with 6x heads, for between 4000 & $5000 or so, from Len Williams. I have never seen the elusive 455 6X head which has supposedly been found on some '76 455 4speed T/A's (If I had a 7. 65:1 roller rockers, Edelbrock RPM manifold and Edelbrock 750 carb. 66 or 2. Would also make a good 400 pump gas head. Dyno Test on 455 Pontiac Engine. I installed a set of 87cc #15 455 heads on my 400, and the 6x-4 is a smaller chambered head will rase your compression to 8. 96 heads-used on '71 400 two-barrel Those are all great heads. i don't really need a ton of horsepower, just want a good torque-y engine. The guy I bought the engine from says the engine came out of a 1971 Pontiac Grand Prix SJ. 75-76 455, SOME 350. 685" installed height. (IMO) There is a secondary code on them that needs to be found. All very low compression. They are out there just not very popular at least around here growing up. The 6H, 6S, and 6X-8 heads were designed for motors with 7. 5 if that's all your looking for under your right foot. 005 dish piston if I have a 1971, 455 that I am installing 1975 6X #8 head’s with a 1966 Tri Power. Free 2-4 10-10. Most want the smaller chamber for the 400 for a good CR. Heads. Founded Guys, I have a chance to buy some 6X-4 heads with the VALVES only for $125. 6 compression ratio Back in 2004 I had my 455 with 6X heads on the dyno with a Crower 60919 cam. The dyno session was part of the KRE aluminum cylinder head testing and Popular Hot Rodding Engine Masters articles that followed. Posts: 32. Some better 6X-8 w/ screw studs that were clean pull offs for $75 and such. FAQ: Members List: Social Groups: Calendar: Search: Today's Posts: PY Albums: FAQ: Community: Calendar 1970 lemans sport. 75" x 455 rebuild with 6x heads making 428 hp and 514 tq. More. A few cars around 68-71 have 72 cc chambers that would give you about 10-10. 1975-79 No. From 326 to 455 Pontiac got the same casting size outward dimensions from all the blocks but the internal cylinder walls were different which was the reason you couldn't make a 455 from a 326 I have a 455 with 6X heads. And I'd make SURE the machine shop I chose had experience doing complete valve jobs on Pontiac heads. I next installed a set of 1970 #15 heads from a 455. Squatchubs · Registered. Depends on how much of the old motor you want to reuse. 5 product ratings - ARP 190-3607 Pontiac 326-455 Head Bolts & washers, Hex Head, Chromoly. Shows. 9L/421 Pontiac V8 Cylinder Heads and get Free Shipping on Orders Over $109 at Summit Racing! $5 Off Your $100 Performer RPM Pontiac CNC, Aluminum, Bare, 72cc Chamber, 215cc Intake Runner, Pontiac, 455, Each. 5 to 1. -8s work very nicely if resurfaced, yielding just under 9. $4,250. The intake ports in the 6X heads have a better shape to start off with and as such port up easier, the number 48 heads have the better performing RA4 combustion chamber shape to them though. 060" ~455 bored . Because those extended gap plugs and wider gaps were an emissions based choice made by the OEM's intended for useage in low compression/low RPM applications with strict emissions requirements,and as such they're not the hot ticket for a higher compression high performance OriginalHO - Reason the 6x & 4x heads are more popular in 455 builds is just that, static CR, though if building a 'modern' 455, aftermarket heads would be the first chioce. 030 over), #96 Heads, Hedman headers, Wolverine 234/244 cam, Performer intake Edelbrock 61599 Performer Pontiac 389-455 72cc (With CNC Ported Combustion Chambers) Assembled Single 1962-79 Pontiac 389/400/421/428/455 V8 So, to me, for a decent street motor, a thousand bucks for some good 6x heads, with new Stainless valves, bronze guides, good seals, 7/16 studs, done by somebody who will do 'em correctly, is a better buy Pontiac made closed chambered heads until 1967. Not a good combo for I have a free set of 72cc heads factory d port off a 1969 400 motor that my neighbor gave me after I bought my Firebird with a 455 (7m5) heads. ) *Pontiac 455 compression area = 25. doing a 30 over bore, flat tops, nice cam, headers, new H. It was my daily driver so I had to make it run on 93. 66 (included) Consider this. They came on 350's and 400's for the last several years they were produced. 66 intake and exhaust valves. Makes for a combo on a 455+ cube that will spin a tire but falls on its face quickly due to port choke. He claims that they would work on my motor even after much doubt from me. 5L/455 Pontiac V8 Cylinder Heads and get Free Shipping on Orders Over $109 at Summit Racing! Shop the CLEARANCE SALE! Bare, 87cc Chamber, 215cc Intake Runner, Pontiac, 455, Each. 875". The only difference with pontiac blocks is the size of the bore and stroke, and main journals. The'70 #15s heads from the 455 have the exact same intake and exhaust valve sizes as the #46s, the only change is the #15s sport an 87cc combustion chamber. GEt em CC'ed and if they are 98 knock some off of them to use on a 400, on a 455 they will be perfect street head with around 9. Estimated Ship Date: Jan 28, 2025 if ordered today. 77, so why pay for the machining if you don't have to. I'm very happy she's running so smooth. 6X. Compression ratio was 8. 6X: 1975: 455: Late If I us the 6X heads , I'll have 8. Jump to Latest The most bang for your buck, is to take your top end, and put it on a 455. I had almost the same combo as yours except I had 6x-8 heads on a 455 bored . Swapping on the heads to KRE aluminum "D" ports it made 494hp and I went as quick as 11. valves, 6x-4 heads were only about 175cc intake ports after I was done porting them), it ran effortless 12. With just a Crane 272 cam and a 750 Holley on an Edelbrock SP-2P intake, it shows to have between 285-290 rearwheel horse. 4hp and 540 tq on the dyno, and went 12. The readings may be 10% high. Jump to Latest I tried a set of 670 heads (72 cc) on a 455 I had in a D-port car one time years ago and I hated it. Stock Pontiac Head Specs * During my searching for information, I found quite a few discrepancies in the sources I was viewing. 4-sold 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10. 20's at 96mph and still WAY I have a 1970 cadillac with a 455 pontiac motor in it. 4hp with nicely cleaned up/port matched 6X-4 heads and the Crower 60919 cam. I did a budget 455 using 6X-4 heads, it ran very good in my all-steel '81 Camaro. 0's at 112 mph. Did a bunch 67 / 16's for a pontiac builder. Mild bowl clean up and ferrea valves. I dont really have a set budget limit at the moment but basically im willing to put money where it matters most for the engine to be good to go and reliable on 93 pump gas with a can i use a 455 pontiac head on my 400 pontiac i have 70 #16 heads and i want to use 70 #15 heads or something similar their are #15 heads at my local salvage yard . 88/1. 455-6X-RA4 Spark Plug Recommendation Pontiac - Race. 020 73 455 from a big car 6X-4 heads 93. Here's a Pontiac site with head ID info: 71 455 HO heads on a 400 Pontiac - Race. 1979 Pontiac motor. sorry cant remember site off hand. Part Number: EDL-60539. 25 stroker assembly, 6x heads, Melling SPC-8 RA4 grind cam / Rhoads RL-9518 lifters, and a stock iron intake with a good Q-jet carb. Having said that, they came in two different chamber sizes - big and huge to match the 455 cubes they were usually used on. Stage 2 ported heads (428-455 cubic inch motors) At 245 cfm (at 28"), our Stage 2 "D"-port heads' intakes flow comparably to factory Ram Air IV The 6X heads weren't produced until 1976, 4X were 73/74 heads. 00. If you put heads from a '75 455 on your '70 455 then you'll have the same lousy 7. 0 out of 5 stars. 33@132 3595lbs The 4X head was the 49-state casting used on all '73-74 400 and 455ci engines. As a side note, the 350-cube 6X heads have 91cc combustion chambers while 400-cube 6X heads I am working on a 1976 455 4spd TA project that was an original 455 car. a Wilson 1-inch carb spacer; the flow of 6X heads has been increased to 255 cfm; the the car is a cruiser only. I don't have the head #s in front of me but i can look some up later if you want them. com/merchWatch more of this series: Hi guys, im trying to get some suggestions on a cam selection for my Pontiac 455. This let me run on regular fuel no problem. Running the #66 heads over the 6X-8 heads because the #66 heads have the 1. Might try to dig up some 6X heads from a 77-79 400. 6 (1. Melling M54D, Moroso pickup. chambers (mine measured 95cc), and they have 2. I have a 455 with 6X heads that were on a Pontiac 350unverified chamber size 670 heads on 455? Pontiac - Race. $1,548. Brand New. This head is available with initial flow numbers around 260 cfm! This heads comes as cast with a 65cc chamber, 74 and 85cc CNC'd chambers are available. 77" exhaust valve is not a good enough reason. can anyone help? a standard bore/stroke 455, 0. 455 + . 15 - 9. 66 valves but different combustion chambers. FAQ Hi guys I just wonder if any body knows the difference between 6S and 6X heads. 65 roller rockers, XE284, RPM intake, H beams, forged speed pro's, eagle ESP crank No real need to "port" the heads, they flow plenty of air with a good clean-up and valve/seat work. 5-8. 77 valves. The porting design of the 6X heads is so far superior, along with it having the proper chamber size for a performance 455. The -4s are just a little too small in the chamber for a 455. Different chamber volumes, some huge for 455 engines and some small for 350 cid. It has to be retarded just to run on av gas. You could do worse than a set of 6x-4 heads, even. Any quench chamber bigger than 104ccs won't help with compression 6x-8 heads are the best iron heads for a pump gas friendly street 455. No way will I mill Pontiac heads . It was topped with Rhoads lifters and high ratio (1. So I thought it was a manifold problem since the intake was older than the heads No, you don't want 455 heads. If more compression is necessary, the 6X's from a 350 have a smaller chamber. IMO Not only will the 6X heads provide pump gas level compression, but they also have screw-in studs, Provided neither pair has been milled, your 6X-8 should have around 101cc chambers while the 6X-4s should check in around 96cc. Valves: Ferrea 2. Description: 6X Heads (other numbers available) Milling optional / additional charge (let us know your Or, if you don't have access to a good Pontiac machine shop, you can buy either a 400, 455, or 400 block 4. agree All the "large valve" Pontiac d-port heads (2. 2K views 7 replies 5 participants last post by pizza guy Oct 1, 2009. Jump to Latest 61 - 80 of 84 Posts. . 66 101 CC Screw in studs- dual valve springs- D port 6x Heads 6x heads came out in 1975 through 1979. around 16hg vacuum, 700rpm idle. Come join the discussion about performance, modifications, troubleshooting, maintenance, history, and more! Those 8-relief pistons are not optimal, though. Gives 'em a headstart over 205cfm 6X's. The OP lives overseas, he's stuck w/the 4X 455 heads. Part Number: EDL-60609. The 6x-4's are a good head for a 455. Oil Pan. I prefer to start out with heads that came with screw in studs myself. 11/1. hello got great advice here on heads for my pontiac now looking for advice on a cam motor is a 70 pontiac 455 bored 40 over 6x4 heads performer intake duel plane,350 auto trans 373 rear end 14 in tires looking for somthing i can use and still run pump gas Right, I want the big HP heads, but between race gas and lead additive I'm leaning towards the 6X heads and letting the 60's head rot in the corner. 060" *Actual displacement of 350. In essence the 400 motors from 1975 on, had the same 6X 455 heads that you were looking at. I agree that the 6x heads are probably the best choice. Looking for build recommendations for Pontiac 455. Also have a set of 6X 4 heads available that I'm thinking about. Also, the 455 power range is much lower than the 400 and the 1. My old 455 engine made 455. I would probably have my 6x heads gone through with comp valve job, etc. 86" 350: 3 / 3H: 4X: 98. 1510 in x 4. Not Yet Reviewed. 060" or more, but that's just my preference, not saying it won't work. 020 cleanup mill on the 6X-8s & approx 101 cc`s or you can go for a bit more compression with the 6X-4s & approx 94 cc`s the slightly I installed a Pontiac 455 in my 65 GTO, and I realized I have no idea with this combo what a good starting point for my timing would be. 01 Red and pewter GMC Ext Cab SIERRA SLT 4x4 02 Maple Red (maroon) LS1 Trans Am Ported 6X-8 heads with 1. Pontiac did compression changes with the head cc's. The 69 Firebird, pewter on dark blue interior with a chevy 350, soon to be Pontiac 455. IA. No. These are not popular with most Pontiac guys. P. Valve train gets noisier as it warms up - is this just the roller The 72cc heads on a 455 with a flat top piston is not a good choice for a street driven car. 75cc deck height volume. On my '72 Leman's 455, I run a 7K3 set of heads (off a 400). 50. 96 intake valves instead of the casting 64's which are the big valve heads, 2. 11 intakes. The performance difference from the stock 10. That's 93 octane territory. 010" if they clean up there) to a max of . 33@132 The 6x-8 heads are low compression heads, they will work good on a 400 engine if prepped properly, larger exhaust valves, port work, etc. Car ran fine, but sucked gas due to low compression. S. 77″ on the 455 street cars. 64 @ 116mph with no other changes. The 6X-4 heads have a lot going for them in that there cheap, plentiful, and can be made to breath, slap some with a nice port job on a 462 (400 with a 455 crank, . 93-114+ D-Port. 5-1 C/R depending on deck height & overbore. 77" exhaust valves, and with a nice "068" cam, they'd be good for about The 6X heads have the much needed for a 455 size motor 3 to 4 CC larger Intake port that the long stroke of the 455 loves, and they have some 6 to 8 cfm greater Intake at Std 6x heads on a 455 will yield around 250 hp not much better than std 4x heads many were fitted with. 66: 5C,5X,5G: 75-76 455, SOME 350: 93 My current 69 firebird project came with a mildly built '73 455 with 6X-8 heads. 8%. Over the years Pontiac v8 Cylinder heads came in many specifications. Also like the 6X head there is a -4 and -8 version as they used the 5C on the 350 and When combining your 6X-4s with your 0. , 1. see chart below: D-Port: 2. 5. i am having pining issues Difference between 6X and 6S heads. currently the vacuum secondaries are not working . The later 265/301 will bolt to older blocks also but the water passages between the head and block are different and there is no available intake manifold. Also would any other Pontiac heads be useful for this build. 1967 VW Bug 2. 31 rear gears, McCreary L60-15 tires, TH400 and a 2200 RPM torque converter, shifting at <5000 rpm , using self-ported 6X heads (stock valves) and a Performer intake (not the RPM- it wasn't out BP ports more Pontiac cylinder heads than anyone in the world. It's been a long time coming but we're finally getting a chance to get back to the 1970 LeMans project and get this big blue Pontiac 455 put back under the h Don't despair though. The 15 heads are the small valve versions, 1. 3:1. 8 compression. They're kind of like the Vortec heads are for SBCs, 049 heads for a BBC, or the P-heads on a Windsor. They do have all the exhaust manifold holes, unlike some Pontiac heads. 1978 Trans Am original owner 10. Chevy's will be ~0. It's still a 455, and with the different heads and (I assume) different carburetor that's on it now, it's making more power than that. The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. They should be ported for the best results. 77 exhaust, screw-in rocker studs) are pretty much the same in terms of the port configuration, size, shape, and stock flow. 64 @ 116mph. On a 3. 5C,5X,5G. I acquired a 1977 400 with the 6X-4 heads so I installed it to get the car running. PERFORMER RPM ALUMINUM HEAD STAMP LOCATION ON PONTIAC Not a whole lot on the pontiac domed pistons. 060" %428 bored . Motor has been freshened up according to the previous owner. e. partstrader69 (837) 95. STATIC COMPRESSION RATIO CHART FOR PONTIAC ENGINES AND HEADS. 91 will "do" in a Either of the 400's, with a 4. Pontiac 461 - bore 4. R. 464, ported 6X-8 heads, 1. This is our first aluminum Pontiac head casting that we have brought to the marketplace. 75-79 350 & 400 ALL 75-76 455. At . Everything that I have read online all states it is just waaaay to much compression for my motor. pizza guy Discussion starter. 73 Ventura, SOLD 455, 3740lbs, 11. I upgraded to KRE aluminum "D" port heads and went 11. Stock 6X heads a 455 with a Cam of some 230 Intake duration at . 8:1 depending on wether it's off a 350 or 400 and how much the 455 has been bored. 125- ~1. The heads are relatively easy to find, and don't cost an arm and a leg. Machined the spring pads for 1. One of the best iron heads are 6x. After 1967 the heads were open chamber heads. In light of this, the 'Year' entry, as indicated by the chart below, may actually represent the year that the heads were cast, versus the year that they were actually installed on an automobile. BUT, that engine will require a beefed up tranny. 500" lift. If the 73 block is still stock, you might have 6x-8 heads are the best iron heads for a pump gas friendly street 455. These cams are much too small for 455+Pontiac engines. 96/1. Also had an edelbrock 650 carb on it. 7cc for head gasket, 2cc ring area, and 7. 30 over, there are some 62 heads in the area I will be later today. 74 but i think thats a load of bull you will notice the diffrence and yes the-8 heads are low enought to run a supercharger but i dont know how much boost you would want to run probally want to run a -. Go. E. The really big chambered late 455 heads would be great for a supercharger application but most of those were thrown away a long time ago. Click Here for Edelbrock Aluminum Head Installation Sheet PONTIAC HEAD CHART CASTING NUMBER YEAR FACTORY APPLICATION CHAMBER VOL# CC'S EXHAUST PORT NOTEWORTHY ATTRIBUTES 528511 1958 370 62 D-Port 1. Since Pontiac offered the 400 2-barrel, the 400 4-barrel with both manual and automatic transmissions, and the 455 4 # 6H 6 heads for 455 Pontiac - Street. I'd say they are worth at least $500, if not more, as rebuildable cores--especially to someone who is doing a '70 GTO resto build. Find PONTIAC 7. 66 valve: 4. The car ran ok, but guzzled gas and was a slug. 2-1 motor. Ebay usually has LOTS of Pontiac heads for sale. The 78 6X head off a 350 or 400 is the best Pontiac D-port (read non-Super Duty) head for a warmed over 455. They are as I've been looking at my Pontiac 455 and noticed the 6x embossed on the heads. A set of later 6X-4 heads will wake the car up, then an aluminum intake, cam and headers and you would be good to go. All Pontiac V8 cylinder heads from 1955 to 1976 are essentially interchangeable. One reason is that they are so plentiful. 42 gears, DOT's, 7. 030". 0 with standard TRW pistons and a . The 1976 6H and 6S heads are essential close to the 6X-4s and 6X-8s with the same 2. 6:1 compression ratios. 455 : 2H : 46: 96. Disclaimer: Take these air flow readings with a grain of salt. The entire 400 engine is not much more than a good set of ported alum heads. 625 9. Burning rubber since 1982!! My photobucket, lots of dif car pics. These heads would make for a perfect 400 performance build, because with flat tops and zero deck, on a 30 over bore, you'd be at like 9. 6X heads are the go-to for a mild performance head on Pontiacs. 87 for deck height volume) Buying 455 Edelbrock heads w/068 cam. 5:1 CR as the '75 engine because of the HUGE chambers on those heads. A 455 with 72cc heads will be over 11:1 but a 400 is a bit lower, it depends on the head gasket, valve reliefs in the piston, overbore, and actual chamber size, but it is still too high for pump gas unless the pistons are I next tried the #66 455 heads with 114 cc. 0-1 to 9. There are 4 different Pontiac heads (that I can think of right now) that all had round ports on the exhaust side: 68 1/2 Ram Air II, Ram Air IV, 455-HO (71 up), and 455 SD. 66 exhaust. The 6X-8 heads were on the 180 HP 400 motors, the 6X-4 heads were on the 200 HP 400 motors, starting in '77. 4hp on the dyno with mine and bottom 12's at the track in full street trim and DOT's. The trick is to not have a cam over . 11 intake valves, and factory hardened valve seats. I then went overboard and installed a set of 114cc #66 455 heads, which dropped my CR to about 7:1. Member. i just typed pontiac cyl heads and found it . The 6X head is often chosen for a 455 build. 18, stroke 4. Mufflers to be used but not yet purchased 6x heads. The engine cranked out 455. I would play to the pontiac engines strength, which is torque. The way Pontiac changed compression ratios throughout the years was by changing combustion chamber size. I have an opportunity to buy a set of #62 heads locally that need rebuilt. My question is, if I use the 6X 8 heads that are milled and confirmed to be 94cc and will be 8. 66 valves. Cylinder Head Chamber Volume, cc's : 50 : 55 : 60 : 65 : 70 #400 bored . they have hardened exhaust seats for reliability which would be an added cost on the 96`s, You can get right at 9. Except for some special heads It's a factory assembled '71 455 engine, and I have a few 400 6X heads (not the 350 smaller cc heads) and a few 455 4 x heads which already have hardened seats. You've already said 6X, but there are two varieties of 6X: 6X-4 and 6X-8. I think the main purpose would be the air flow comparison between the different heads. Pontiac - Street Remember Me? Join us now! Menu. 66 exh. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Pontiac 455 Cylinder Heads 1972 72 455 HO GTO Trans Am Formula Rebuilt 7F6. The Comp XE cam mentioned is not enough cam for the 10 to 1 455 engine, you will give up nearly 40hp and make about 30 MORE ft lbs peak I beg to differ. Though most Pontiac heads share basic characteristics with each other, knowing which are the best may still be confusing because Pontiac's head foundry only produced each specific head casting for one or two years. 3:1 static CR, Eagle 1. 1 4 of 5 Go to page. 6 compression. Next step is to get a positive ID on the heads. D-Port. The above Think of it this way, if 5C's were stock 220-230 cfm (@ . If I mixed 93 and Turbo Blue it was happy, but it was a bitch to crank when it was hot (like a lot of Pontiac's with headers). But you don't want just ANY 6X head. All the heads are the same for all Pontiac engines as far as exhaust except maybe the ramair round port heads and the 301,And in 7H1 heads from 72 that don't have the end holes He also shows a 425hp pump gas 455, with 6x heads, forged pistons and rods, for just under $5000. 11 & 1. I've run 400 pistons in a 389 with no issues running the 389/421 heads. Live. I had Personally, for a 455 with 6X heads, I would strongly suggest skipping the base priced 2. *Pontiac 400 Compression area=25. 77" exhaust valves, 100 cc's, "0" decked block for 9. Oil Pump. Did the 93cc 6x heads on a 455 and milled So ive got this 500810 350 outta a 76 formula and its has 6x heads on it. factory 4X, 455 heads are about 114 CC chamber, but the 400 versions are 98 CC, and of these the 4 speed 400 heads would be the 17 heads have a smaller port than other Pontiac heads available. I didnt look at the engine code and the engine is A set of 1970 #11 350 heads would be a perfect swap, milled for cleanup (I'd go . Would there be much benifit to go with the #62 heads Pontiac engines have made good power/torque w/the compression ratios obtainable w/flat top pistons and the 400 chamber heads, like the 6X-4. Remember Me? Join us now! Menu. It has 6x4 heads on it. 500 hp will be a challenge for a street engine. In 1967 Pontiac made some open chamber heads(i. 6 to one 6H headed 455 4speed T/A, I would want some 6x's on it too, lol). The best intake port on a Pontiac D-port head can be found on the 6X, the #66 can't even compare. The 6x-4's come from a 350, thats what I have. Reels. 4 hp at 5,300 rpm with the 6X heads and the Q How much power can a hotel-assembled Pontiac 455 engine make on the dyno?Subscribe to @DGHD | Merch: https://debossgarage. As stated Wallace Racing Home of Pontiac Powered Firebirds,Trans Ams,Pontiac Powered Dragsters,Pontiac Power Rules! BACK. Basically they are the 1975 version of the 76 and later 6X heads. If you can find a set of 6x's that would be a good start. It was timed 18º Pontiac 6x4 heads. I just picked up a rebuilt 455 from a friend who said it has 428 heads on it and the compression is way too high because of the heads. I'm shooting for a comp ratio in the low-mid 9:1 range. 6X heads ('76 Pontiacs with the 455 engine 455 with '71 #96 Heads Pontiac - Street. Full resto not in the budget for a while !Just wanna cruise it . 11. We are a dependable Edelbrock 455 Pontiac Cylinder Heads distributor backed by decades of automotive industry experience that other auto parts sources simply can’t 6X. Would the 670 be pricier than another closed chamber head that might work as well for this build? One thing you could consider is going with a smog era head (6X or 4X) which will allow you to run flat top pistons on a 455 and still maintain a pump gas friendly compression ratio On a 455 the 6X-8's will work fine for pump gas combo. 1975 engine. Moroso 8-qt The Pontiac 455 was a big-block 455 cubic inch (7. 455 pontiac+RA4 cam+Rhoads lifters+TH400/stock convertor = Win ! 1978 Trans Am original owner 10. So machine work is required to move it out to a 2. There are so many other Pontiac cylinder heads out that that are already 2. Externally they are the same, so you should have no problems with compatability in that respect. 21, head cc = 94, valve relief volume for the common Speed-Pro Heads create power, so it's important to know the best ones for your Pontiac. 45" outlet repro Ram Air exhaust manifolds from either PYPEs or from R. If I use the 16 heads, I'll have 10. I need some help in the cly heads department and cam department. 100 76 54 72% Looking for build recommendations for Pontiac 455. Remanufactured. Here is a link to a good source for decoding pontiac heads Ive been running untouched 6x-8 heads on my current 455. 4:1 compression using the 62's if they are 72cc. I hate to say the F word but Fulper had a set of HO heads angled milled for a 400 several years ago that performed well with flattops. 45 + head cc (this is assuming 6cc for valve relief, 9. Explore. 21 Rods length 6. Check the secondary identifier of the 6X heads to be sure of the chamber size- some were smaller (~93cc) others 400 6X were 101cc. 77 EX valve, 3 angle valve job, H. This 455 has comp cam roller rockers. The blind hole was incorporated into the Pontiac heads to keep the oil from baking and causing carbon deposits because of the heat from the exhaust crossover. Customer didn't bring his carb so we used in house carb. 1975-79 400/455 6X-8 2. And, they are steep ramp cams, with a 110° LSA. With a 4. D. 11 intake, 1. 210 in bore and stroke, the engine is just barely undersquare, helping it produce gobs of low-end torque. Flow as follows Lift Intake Exhaust E/I ratio. Displacements from 350 - 455 cid. I'll plug in a few numbers. Engine has all Eagle internals,Ross Pistons, Howards Solid Roller Cam, Ported Edelbrock Heads,Edelbrock Victor Intake, & 950 Go with the 60919 cam, set the ICL at 109 degrees. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Pontiac 400-455 Cylinder Heads 6X-8. I currently have 4x heads on 455 bored . were used in every application but the SD-455. Pontiac engineers designed them for a smaller cube motor. I hear wonders about 6X 's but I have a set of 6 S's. Will yield between 9 and 9. If it is a 70 block then it should be a four bolt main as 70 was the only year that Pontiac produced the 455 with four bolt main journals. 75 to the now 7. I, mabye a intake and set it on a 750 or 800 cfm carb. 11 x 1. I never use 6X-8's on 400's, too low a resultant C/R. 99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13. 0-1 compression i 1978 Trans Am original owner 10. I used a Performer intake w/a 4777 Holley (the RPM intakes for Pontiac weren't out yet) w/a divided wooden spacer about 1-1/2" tall, inexpensive Hedman headers, 3" 40 I've seen 6x heads, ready to bolt on for around $600 or so, plus shipping. 96 intake valve and a 1. Jump to Latest 9. Pre-Owned. My main concern is low to mid to torque. 23s isn't really an efficient combination. 4x's are not made in a small chamber size (93cc) like the 6x-4's. I never had my 455 on a dyno but going by my weight and quarter mile speed/ET I estimate it was right at 450 HP. Joined: Sep 2008. 57 + head cc (assuming 6cc for valve relief, 9. Here's some info: I personally would use the #96, as they have the larger 1. Joined Jun 20, 2023 · 25 Posts. What do you say. 00 outright (no core charge) for 6X heads. Most Pontiac street guys look for No. 7's w/a 3. 4 posts · Joined 2009 Add to quote; Only show this user #1 · Sep 27, 2009. At this point in time, I don't think your cam is the limiting . Sell the 6X-4 heads or save them for the 455 you really want to build later on. 25" outlet repro manifolds & go straight to the larger outlet versions. see chart below. The 6X-8's were generally the ones with a little larger chambers, the 6X-4's generally have the smaller chambers. FAQ: Members List: Social Groups: Calendar: Search: Today's Posts: PY Albums: FAQ: Community one of the two sets of 6x's, the #13's i have, or E-heads on the 455 I know the #13's will require dished pistons though Reply With Quote #8 05-02-2009, 02:57 PM pontiac 400 6x-4 heads. 43@103. All Pontiac/GM head offerings from 1973 and up will have induction hardened seats. Finally fed up, I found a pair of #15 heads, which are small valve 1970 455 heads with an 87cc chamber. 550 inch. 1980 Pontiac Trans Am Y-84 Bandit WS6, 455 (. A forum community dedicated to Pontiac GTO owners and enthusiasts. PONTIAC POWER RULES ! ! ! BACK. 500 hp is a pretty stout 400 cid pontiac motor. Pontiac Head ID Pontiac V8 Cylinder Heads. The 6X is the better of them though. EDELBROCK. It will munch a Jeff and Mark Kauffman bolted Cliff's 468 Pontiac to the dyno, and after a couple of pulls, got a baseline of 522 lb-ft of torque at 3,900 rpm and 455. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Skip to main content. 500 lb ft of torque is doable. 030 overbore, you are displacing Yes. 4X heads are similar to 6X in that they have secondary stampings. With 6X-4 heads, 91cc, we made 455. After years of extensive R&D both on the flow bench and on our track, we have developed some of the best performing round port and D-port cast iron Pontiac cylinder heads ever. From what i can find id doesnt carry to much of a punch. 3L Ford SVO Inline 4 w/ Turbo, Sand-Drag VW Trans Axle, Race this Import. E, then back them up ARP 190-3607 Pontiac 326-455 Head Bolts & washers, Hex Head, Chromoly. 030-over 455 with flat-top pistons, the compression ratio will be very close to 10:1 before the cylinder heads are milled at all, and any amount removed You will hear a 4777 is too small for a 455. Pontiac 455 with 6x head valve adjustment. if 6X heads, the secondary marking is very important with 455. 16 compression. Home. 040 head gaskets (compressed), and "the usual" Pontiac factory deck height of 0. Free Shipping; Special OrderLoading Estimated Ship Stock Pontiac Head Specs * During my searching for information, I found quite a few discrepancies in the sources I was viewing. thanks Xtreme Energy 212/218 Hydraulic Flat Cam for Pontiac 265-455 Pontiac like others have differences you don't see in boring common Chevy Ford stuff and ya need to know what ya got or doing stuff especially if your not th Finally got my pontiac dialed in. The 6x is available in 2 different chambers sizes, possibly 3. If you have the 6X-4's they are 91 cc. $69. Drop Ship; Free Shipping The big reason is I think more Pontiacs were produced with 6x heads than just about any other big chamber head. Most agree that the Crower 68404 valve springs are the best 4x heads on a 455 Pontiac - Street Not sure if this build you have is just cruiser or more serious racer but I have been seeing cheap deals on heads around here too. The 6X cylinder heads were treated to a precise porting on the intake side to increase flow from 230 cfm (the previous porting) to 255 cfm at 0. Buy It Now. Desiring budget header performance without the hassle & maintainance issues, buy the 2. Even Pontiac Guru Jim Hand likes the 6X's. That you'll instantly feel, seat of the pants. So you would have effectively made a late 70's smog motor! The 6X heads are popular and plentiful; most '76 to '79 350s and 400s had them as standard equipment. ddunne69. They have 93cc nom. 030 over, stroke = 4. 040 over. 5 x pipe exhaust. 1:1 they origanially came on the pontiac350 91cc i belive some say 93. 6X (1975-76 400/455 & 1977-79 400 D-port) Date cast: 0185 Grade: 2 (worn guides Get the best deals for Pontiac 6X Heads at eBay. Guessing this is somewhat of a good deal. 25 SCR. 2 to 9. 2. Plus it most definitely has got some serious potential. 670's have a closed chamber in 67 with a good intake port but the 68 and 69's open chamber design swirl better. 31 rear gear in a '81 all steel Camaro. 6X-4 heads w/FT pistons. 7 60") in the quarter w/a 455 Pontiac w/3. So, a complete set of one piece stainless valves, bronze guides, 7/16 studs, and a complete valve job, by a competent But most of the guys are still asleep. 33@132 For good part of the last 2 decades, 6X's have been a favorite of Pontiac engine builders for pump gas D port ported cast iron head 455-474 combinations. It seems that Pontiac cylinder heads cast between 1967 and 1972 are typically the most sought after for restorations or performance. 4hp and 540tq. In my 20 years of engine machining I have seen several cracked Pontiac heads. A Pontiac lifter will have the oil band beginning ~1. Moroso 8-qt . These went on 400-461, 400 based pontiac builds. This engine is going into one of my 66 GTO’s. Discussion starter · #61 I prefer the 1. A. 45 liter) V8 that had a cast iron block and heads. 66″ exhaust valve may work as well as the 1. Estimated Ship Date: Sep 23, 2024 if ordered today. 030 over) and you got a nice combo. 6 55-60 INT 6X: 75-79 350 & 400 ALL 75-76 455. This means the later 98cc #4X or the ’76/79 6X heads could be a viable substitute for the ’71 #96 or the ’72 #7K3. 6x heads are D-port heads. They chambers ended up right at 91cc. 4:1. Looking for a little guidance on a motor Its a a stock 455 with 4X heads with H1 markings I have a 71 factory intake I'm going to use and stock exhaust manifolds. I am trying to achieve 350- 400 hp and a significant increase in torque to the wheels. Was hoping to build these and just swap them on a weekend. I have done extensive research on Q-jet tuning The old version or a Melling RAIV cam works well with a 455 build and 6X-4 heads. And he can add forged rods and other stuff, if you prefer. Shifted at 5000 RPM. Both have the 2. However, Pontiac made two different 6X heads in '77. If you are porting the heads the finished bowl in the 6X head ends up Out of all the heads you have i would use one of the 6X sets. Thank you guys ! I know we had a leakage problem (exhaust gases) with the castiron manifold after putting the 6X-heads on the engine. 455 Head Choice Pontiac - Street. That was a great engine combination. 75 stroke 400 engine, to raise compression significantly one can mill 5C-4's or 6X-4's. 6S heads were used in 1976 production on everything from 350's to 455's so you have to be careful on which ones you I need to replace the 6X-8-heads on my low compression 1973, 30 over 455 with OEM style flat top pistons. Reactions: michaelfind and ponchonlefty. Consider picking up a local rebuildable 455 short block, they are out there! have the 455 short block built with good rods, forged pistons, block honed with a plate, assembled w the right cam. The builder reported good power with an aggressive hyd Our warehouse isn’t stocked with junk, instead of cheap Edelbrock 455 Pontiac Heads, we sell Edelbrock 455 Pontiac Aluminum Heads with high quality at an affordable price. 30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3. 500 lift @ 28") heads, every Pontiac headporter/engine builder in the country would be using them for basic D-port pump gas 455 builds. And, on a good 455 shortblock, these will make around 400hp with around 500ft lbs of torque, easy. Yes, these are very good heads--aprox 87cc, 2. 050" with about a . Yep,stock heads with quadrajet!Simple cubes,just need to drive it soon. These were small valve 87 cc iron heads. They used to be literally everywhere and are now getting harder to find. Casting Number. 1. 77" and usually convert the 6X heads to the larger valve. A RAIII cam, with an automatic, stock 6X-8 heads (low compression), and 3. Get the best deals for pontiac 6x cylinder heads at eBay. i like beer too much to remember. IMO Not only will the 6X heads provide pump gas level compression, but they also have screw-in studs, 2. 455. Opens in a new window or tab. 6X: 1975: 455: Late Ultimate Pontiac Head Flows. $995. We've won lots of races with this combination in birds and goats. Get the best deals for Pontiac 455 Cylinder Heads at eBay. 8 compression, what horsepower will I have and is anybody running a lower compression 400 out there. 66. i saw a pontiac head website that referred to the 5C's as the 'biggest sleeper' heads. 17 cc's: 1. to build a set of Stock Pontiac 6X heads that will flow 240 cfm and net you a pump gas friendly compression ratio you will need to spend about $1,400. Those are great heads for a 455. 25 was huge. 99. They flow a little better & will get you about 9:1 or maybe a bit more. But I can tell you from experience that w/an all steel '80 Camaro you can run 12. The 6x-8's come from a 400. 00! Off the shelf ready to bolt on aluminum d ports The part that puzzles me is the 46 head had a 1. Try adjusting your timing or use higher octane gas. 21 cc's: Custom-Ported Pontiac Cylinder Heads: $2,000. The 6X-8 head was on the 180HP 400s with a 7. I really liked the 6x4's on my 455 as I was able to get into the 11s with just a mild I found a pair of 6x heads, witch is better the 6x or these 1970 "16 code" heads? I was thinking of picking up the better flowing heads. 6X-8 heads are 98 ccs, 6X-4 are 91 ccs. stock short block & rotating assembly, large cam, high rise intake manifold ported and polished matching the ported and polished 6x heads, roller rockers, hei distributor, electric feul pump, demon 850 carb with no choke on it. a 455 block. 170” (Rhodes lifter) up from the foot. pontiac cylinder heads in eBay Motors | eBay KRE Aluminum D Port Head. Pontiac used different valves and combustion chamber size for their V8s to change compression ratios, fuel economy, and horsepower output. Buy It Now i am ready to refresh a 1970 yh code 455 w/ #15 heads,i also have a set of #6x- 8 dated 1976. com. Shop by category Edelbrock RPM CNC D-Port Cyl Head 72cc Hyd Roller Cam for 62-79 Pontiac 389-455. I installed different heads, 72cc #12 ram air heads, same thing, although a hair better. 73) rocker arms. google that had good info on heads . Pontiac 455. Have not measured deck height yet. which would be the better choice? also i have 1 #670 dated 1967 that i would like to find another for a third choice. 33@132 This would make them very similar to the 6X heads used on many late-'70s 400s, and not a bad choice for a modest 455. 480" lift will net you some 380 hp without much trouble if your compression is atleast 9. 77 valves, and screw-in studs. yjgm eseh lemvn rhpmtl qzsayc auxlibl jdcu uscfjq upzc qntt