Since you appear to be in the market to hop up your 455, I also recommend Jim Hand's book on building Pontiac engines for some light reading.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
Bill, this will be my last post regarding your 455 as you aren't listening anyhow.
6X-4 heads, which were low compression 350 heads, are good on a 400. 6X-8 heads, which were low compression 400 heads, are good on a 455.
Buy what you want but don't complain about performance or tuning issues, or how you've been "ripped off", if you don't do your homework and decide on what you are building before you start shopping.
Vikki
1969 Goldenrod Yellow / black 400 convertible numbers matching
Bill, this will be my last post regarding your 455 as you aren't listening anyhow.
6X-4 heads, which were low compression 350 heads, are good on a 400. 6X-8 heads, which were low compression 400 heads, are good on a 455.
Buy what you want but don't complain about performance or tuning issues, or how you've been "ripped off", if you don't do your homework and decide on what you are building before you start shopping.
Yah. Bill is right on with his research and Yellowbird is mistaken. He asked all the right questions when buying the heads. He bought my 6X-4's. They were the original heads on my 79 TA WS6 4 speed car. For a reference, look at the last head listed on this chart. http://www.pontiacstreetperformance.com/psp/heads.html
They were used as 350 heads from '76-78. Look at the same chart. Yes, they were also used on a couple of 400s, most of the 400s got 6X-8.
If they measure out at 87cc they should be okay with premium fuel with a standard bore 455. If he ends up boring it or if the heads have been milled he's going to be pushing closer to 10:1 again. Maybe that's what he wants, but even a stock 455 will haul a Firebird around pretty well.
This is the fourth set of heads he's bought for this project. Dunno about you, but I find it cheaper to plan first then buy.
Vikki
1969 Goldenrod Yellow / black 400 convertible numbers matching
Agreed, 6X-4 are good on 400s and 428s. I have a set on one of my 400s.
I guess I should qualify my remarks as my opinion only.
I am sick of paying over $5 a gallon for racing fuel. I am tired of spark knock if I put my foot in it unless I compromise timing when running pump gas. I am building a pump gas engine that will run full timing and put out more power than is needed to have fun on the street. And it will be all Pontiac power. No aluminum heads, intakes, or aftermarket carbs or headers.
One is just done at the engine builder's. It's a numbers-matching engine at 9.8:1 compression. It'll be installed and broken in within the next couple of weeks. Once the car is back together I'll put it to a road test.
The engine for my '69 will be a bit lower compression with a head swap. I want to see what I can do with 89 octane.
Vikki
1969 Goldenrod Yellow / black 400 convertible numbers matching
My car runs so perfect the way it is stock I wouldn't change a thing. Add a little racing fuel to 93 and I'm golden. Not bragging, just pointing out that it can be done the original way. Sweet running engines when they are bone stock. Sure, you will pay $20 less than me for a tankful. That's only a few hundred a year. Cheap!
The 9.8 to 1 engine is pretty much stock config. 2262F, 068 blueprint, Cliff Ruggles QJ, stock 16 heads rebuilt with hardened seats, Dave's Small Body HEI. Sweet setup, stock look, factory parts with a few tweaks. And still on a modest budget, especially for a performance engine.
My '69 gets a lot of street abuse on cruise duty. Hours and hours of idling on hot summer days (in a 400 auto with A/C)...no room for high strung beasts there. I keep a fuel log, dates and dollars and mileage. It won't take long to pay for the rebuild in fuel savings plus I can have fun again nailing the pedal when I'm finally on an open stretch of road.
There is no "one answer fits all". If someone is not a proficient tuner, an engine with a milder configuration might be safer, better, and more satisfying than one that needs constant tweaking for conditions.
Vikki
1969 Goldenrod Yellow / black 400 convertible numbers matching
Vikki. One thing you need to consider for both of your motors is 0-deck. Please take a look at this from Cliff Ruggles.
would zero deck the block vs milling the heads. There are other side benefits from this procedure. Having the block decked/squared will insure that the distance from each head to crankshaft centerline is the same. Although Pontiac blocks are usually much closer in this regard than other brands, few are perfect. For medium compression engines built to use pump fuel it becomes much more important to maintain the quench distance of .035-.040". The engine will also run cooler zero decked. Without exception, every Pontiac engine I've had in here that had running hot/overheating problems had the pistons .020" to .030" in the holes.
The following is a recent example: We just finished a well prepared 400 engine for a 66 GTO. The owner is a very competant mechanic by trade, he owns several older high performance vehicles. Last year he completely rebuilt his 400 engine with catastrophic results. A set of #62 heads were used with stock replacement cast pistons, Summit 214/224 cam, Torquer I intake and Edelbrock 750 carb. The engine ran so hot he could not drive it. It also detonated under all circumstances, after an entire summer of tuning without improvement, he removed the engine and brought it here. We made a few minor changes.
The #62 heads were mildly ported, combustion chambers polished to a mirror finish and the exhaust crossover filled with aluminum. The cast pistons were the 8 valve relief replacements and were .030" in the holes, they were replaced with TRW forgings and the block was zero decked, a set of .039" head gaskets were used. A larger 221/229 cam was installed with HS high ratio rockers. The Torquer intake was replaced with an RPM. An 800cfm q-jet and HEI distributor were prepared for the new engine. The new engine manages pump fuel without problems despite being slightly over 10 to 1, compared to the previous configuration being closer to 9.5 to 1. It never gives the first indication of wanting to go past 190 degrees even on extended cruises at freeway speeds. The previous set-up would continue to heat up on extended cruises eventually reaching over 220 degrees where it had to be shut down to cool off.
I know that some of you suspect that it is the TOTAL package that changed the results. About 5 years ago I had a nearly identical 400 engine in here with the same history. I DID NOT rebuild the engine, but spent countless hours trying to tune it to get rid of the detonation/overheating. This included a new (expensive) radiator, waterpump/pulleys, several types of fans, etc. When I finally threw in the towel and pulled the engine, you guessed it, the TRW forgings were .032" in the holes. The engine was zero decked, slight cam change and no problems thereafter.......Cliff
vikki all i asked was what cam would be nice with the 6x heads on a 455, i have never asked this question because i just bought the 6x heads.so if you do not want to reply dont, Im sorry i have anoyed you but the question was not about heads. i do not no why we are back to heads can any one tell me what CAMSHAFT would go nice with a stock 455 with 6x heads. Thanks
ok motor 1975 455 stock bore.elderbrock performer intake. 6x4 heads. headers. flowmasters..turbo 400 stage 2 shift kit. 8.2 Bob rear end eaton posi unit. 355 gears 14 inch tiers.
ok motor 1975 455 stock bore.elderbrock performer intake. 6x4 heads. headers. flowmasters..turbo 400 stage 2 shift kit. 8.2 Bob rear end eaton posi unit. 355 gears 14 inch tiers.
Sounds like a pretty good set up. 2.25 or 2.5 exhuast? I would use a 068 w/1.65 rockers.
With a stock 68-72 iron intake, or a RPM, and 2.5 exhaust, a RAIV duplicate w/1.50 rockers would be better.