short block pontiac

[hooligan69]

Want to get a short block and this one from butler is in my budget http://butlerperformance.com/i-25537100-butler-performance-budget-short-block-kit-400-block-406-412-cu-in-unassembled.html?ref=category:1234783

would ram air 3 heads from a 68 gto be suitable??
also could anyone recommend other pontiac engine specialist please

thanks

[67GTO4SPD]

'68 RAIII heads a nice choice, if you are staying with factory iron heads. They are about the best of big valve, high compression D ports. Making 1HP/cu in is hard not to do with them in stock form, even with a mild, but well setup combo. There are several head porters out there that can turn those into 600HP heads, depending on how wild you want to go. Of course there are lots of choices of aluminum heads for Pontiacs these days too. KRE, Edelbrock, Roland Racing CV1, Wenzler, All Pontiac, DCI, and McCarty Racing are all making aluminum Pontiac heads currently.

As far as other Pontiac specific builders/vendors, check out these:

Kauffman Racing Equipment
http://www.krepower.com/

Paul Spotts Performance
http://www.spottsperformance.com/

Sandoval Performance
http://www.sandovalperformance.com/

I've dealt with all of these guys, and there's no bad choice.

[hooligan69]

read somewhere that my 350 heads are the same as ram air 3 ???
also may go for a 460 stroker now so will these heads be ok ???

[OLDFLM]

Best Advice = Buy this book before you spend ANY money...

https://www.amazon.com/Build-Performance-Pontiac-V-8s-How/dp/1934709948

FWIW I ran #13 heads on a 406cid Pontiac for years and loved it. 9.5:1 compression and pump gas.

Did you order the book yet?

[hooligan69]

got the earlier edition already

https://www.ebay.co.uk/itm/How-to-Rebuild-Pontiac-V-8s-by-Rocky-Rotella/332508854540?epid=114405006&hash=item4d6b12790c:g:WS4AAOSw4CFYw8Kl

[pontiacbird]

Want to get a short block and this one from butler is in my budget http://butlerperformance.com/i-25537100-butler-performance-budget-short-block-kit-400-block-406-412-cu-in-unassembled.html?ref=category:1234783

would ram air 3 heads from a 68 gto be suitable??
also could anyone recommend other pontiac engine specialist please

thanks



note that this block is a 557 cast, a light version of the 400. your set-up should be moderate. I would speak with butler

[Skip Fix]

The 557 casting is kind of hit or miss on how much HP it can handle. Mine with my RAIV heads makes about 400 HP and was raced for about 8-10 years fine. A buddy has one as a dyno mule that has made in the high 500 HP range. On the flip side lots of guys esp if a stroker crank have broken mains out.

The heads we need the exact casting number 12s, 13s or better a chamber CC exactly. Over 9:5 -1 CR is pushing it on pump gas -my RAIV 400 made more HP with race gas needing more octane than pump gas. Also by the time you buy new valves, spring cleaned magnafluxed valve job +/- porting you are almost at what a new set of aluminum heads cost and they flow better and weigh 36lbs less EACH! Weighed them myself.

[72blackbird]

No. 48, 62, and 670 heads are also good choices- all have small chamber (70-75cc), big valves, and screw in studs. I do agree that they are getting costly to buy, since most Pontiac guys are looking for them and the buy-in is not cheap. The additional money spent porting and fitting them with good quality stainless valves, bronze guides, 3-angle valve job, and decking will push the total cost close to a set of aluminum heads. And out-of-the box aluminum heads will flow better too.

Avoid the no. 500557 400 COMPLETELY- it has thin webs at the main saddles, and is prone to cracking at the main cap dowel pins. Any pre 70 400, or no. 481988 400 block is what you want to start your performance build with.

Geno

[hooligan69]

going to push the budget and go for a 455 4 bolt block now.. blew the rear seal in my 350 the other day so might as well strip this and use what I can...thats why im asking about the heads???
fella i know has some ram air 3 heads from a 68 gto for sale but are they much better than the 350 heads from a 69 firebird????
at a later date i will go for aluminum heads but ££££££££

[OLDFLM]

RAIII heads were from 1970 (#12)... for a 400 those 72cc heads would be great (9.5:1cr) but on a 455 they won't be pump gas friendly at 10.5:1cr.

If running a 455 you'll want to stay around 87cc's so a set of #64s from a 1970 GTO or Grand Prix would work well... whatever you get make sure they have the 2.11/1.77 valves.

A good friend, Lee Atkinson, ran a 455 with #13 72cc heads to 11.3's in his 1st gen Firebird, so it can be done, you just have to watch the chamber size, quench, and compression.

Jim Hand/Rocky Rotella's book tells you what heads will work best with 400s vs 455s... you can also look up cylinder head codes,valve size, and cc's on line:

http://www.wallaceracing.com/head1.htm

HTH

[72blackbird]

There are more than a few good choices to cap a 455- all of these have 2.11/1.77 valves and screw in studs. 6x-4 (92-94cc), 6x-8 (96-100cc), and no.96 (92-96cc). 6s-7 heads (96-100cc) are similar to 6x heads, but have provisions for emissions- these can simply be blocked off with plugs. The suffix number on the heads are located on that square machined boss on the side of the head (ex. a 6x-4 will have a "4" stamped on that boss). It's still a good idea to have the heads cc'd to get your exact chamber volume.

Speaking of quench- Pontiacs often had poor piston to deck clearances, typically .015-020" below deck. A .005" or zero deck will greatly improve quench characteristics and improve resistance to preignition and detonation.

Geno

[hooligan69]

3 things

would a change in pistons on a 455 make it ok with the 350 or 400 heads

being from the uk 2nd heads will be almost impossible get

and petrol is 97 octane if that helps

[OLDFLM]

Geno, he's obviously not wanting to go to a zero deck if he's entertaining running 350/400 heads on a 455 block... he's going to need that .020" in the hole.

Hooligan69... bud... you're kindof all over the place now. What heads do you have now? We need year, casting numbers and valve sizes to help you make a decision on where to go next.

From there, if you're dead set on staying with the heads you have "in hand" we can try to help you figure out the camber size of the heads you already have and go from there.

WE don't want to see you waste a bunch of money on a short block that won't work or run with what you're trying to make work on a budget... I've been there/done that... and would love to help!

As would others here... let us know what you have to work with (heads) and then we can recommend which short block to go with that will work in the real world within your budget (?)

Not trying to be abrupt here mate... just wanting to help!

[hooligan69]

best i get my heads off and get all the info you need and get some details from the ram air 3 heads.....
but probably best to get aluminium heads and take a beating from the wife......

[72blackbird]

Hooligan,
Running RA III heads on a 455 was how hot rodders did it back in the day, when "hi-test" was available here in the US- but since you can get 97 octane, that does help alot. But 11.25:1 compression 455 might want more octane, especially when it gets warm. Of course , the cam you run and the total timing you run will have alot to do with what octane your engine wants. IMO it's better to err on the side of caution and keep the static compression in the 10.5:1 range with iron heads. If you went with Edelbrock heads, you can go with the 72cc chamber version, since you have 97 octane- no issues there with 11:25 SCR E-heads. A mild roller cam, or even a decent hydraulic flat tappet cam will get you an easy 500+ hp.

I'm running E-heads from SD Performance on my 455- milled down to 85cc, CNC ported to flow 325 cfm. I'm running SD's "Road Paver" roller cam- with a T-II intake, the combo is good for around 625 hp, even on 91 octane.

Geno

[yellow1098Greg]

For the better blocks...how is the 70 400 9799914?

[72blackbird]

For the better blocks...how is the 70 400 9799914?

Early 400s are good too- stroke it with no fear.

Geno

[Skip Fix]

You do NOT want to run the piston way below the deck to reduce CR-it kills the quench that helps reduce detonation. tried it rattled like heck if no race gas added.You can get a dish piston or even machine a dish into flat top TRW/Speedpro pistons to accomplish the same thing.

[67King]

Hooligan,
Running RA III heads on a 455 was how hot rodders did it back in the day, when "hi-test" was available here in the US- but since you can get 97 octane, that does help alot. But 11.25:1 compression 455 might want more octane, especially when it gets warm. Of course , the cam you run and the total timing you run will have alot to do with what octane your engine wants. IMO it's better to err on the side of caution and keep the static compression in the 10.5:1 range with iron heads. If you went with Edelbrock heads, you can go with the 72cc chamber version, since you have 97 octane- no issues there with 11:25 SCR E-heads. A mild roller cam, or even a decent hydraulic flat tappet cam will get you an easy 500+ hp.


I konw this is a a few months old, but just want to point out that most of the world runs RON octane rating, rather than (R+M)/2. His 97 RON is pretty much equivalent to our 92.

[yellow1098Greg]

Just bought the 461 all forged with H beam rods and Ross flat top pistons for the block I mentioned earlier. 4 bolt main but the dam main caps from butler were 800$..ouch