[Jack Ferris]

The 041 cam runs very well in the low compression 455's. Probably not the best choice and if you are using an auto trans then it will feel like a slug unless you have some convertor behind it. But, they do run well.

[Formulajones]

I agree with Ferris.

I'd definately want some converter behind it if you run an auto.

[1971455HO]

I have an HO car I've owned for 33 years. I modified it 25 years ago before I even give a damn about the internet and what was out there. I know there is a taboo / stigma attached to cutting the round port heads, but I done it anyway. If you want it too absolutely romp and dont want to deflower your 7F6 heads, you can go this route...

Buy a set of Edelbrock Performer aluminum RA IV heads from Butler. They can machine them to any level of performance you are looking to have. Tell them what you want and they will give you a price. There are several other guys who do head work on here that are just as capable as Butler. So just do your homework and slap an 041 cam in that jessie...you'll love it. You'll also have to fatten up the carb a bit also. If yours is a matching number HO carb, and you don't want to modify it either...contact Cliff Ruggles and tell him what you are building and he can make you a carb that will match your build.

I brought my compression up by replacing my pistons with +0.030" TRW flat tops and angle cutting the heads down to 105CC. The TRW's set higher (taller) in the hole than the stock Pontiac's and give you a virtual "0" deck height without decking the block. My 191 heads were mildly ported, back cut and given a 3 angle valve job. I took it from 8.4 to 9.2. The RA IV cam would work a lot better with CR at 10:5 or even higher. You can do that with no problem with an aluminum head motor and suffer no detonation problems. The RA IV has 87 degrees of overlap built in it, the higher the compression, the better.

One guy said with no engine mods done...you will experience a little sluggishness in the lower rpm range, he's right, you will, for about 1 second when you kick it. If your already in the 2500 rpm range, you'll never know it.

If they would have had the Edelbrocks 25 years ago, I would have been on them with both feet.

All the stuff you asked is purely left to guess work now days. There isn't high octane pump gas. Except for racing fuel (5-6 bucks a gallon) so there is no way to answer you. Don't be afraid to go with a RA IV cam though. Pontiac would have stuffed them in all of their round port motors if it hadn't been for the damn dawning of the Ralph Nader era & the fledgling EPA polution police.

my $0.02

[rexs73gto]

I know this is for the firebirds , but I have to add this. I have a 73 GTO that I wanted to build it as close to an SD car a possible because when I ordered the car I ordered an SD car but of course the order got canceled several times before it was gone for good. I took a left over they had on the lot. After driving it for 29 years with a few mods I built the engine thats in there now. E-heads SRP forged pistons, Cranes Blueprint RAIV cam, Eagle H-beam rods, 1:65 roller tip rockers, RAIV exhaust manifolds, Performer RPM intake, roller gear & chain, Pertronix ign., a modified Q-jet, X-pipe exhaust, M-22 4 spd. 3:73 rear gears. The heads are as they came out of the box, the engine has been completely balanced within 1.5 grams total, block decked just to make sure it was completely level front to back, side to side. I don't know how far the pistons are in the block. OH, this is a 455 + .30. This engine runs really great. It is faster then any SD I've ever got to drive. The car runs 11:50's at an avg. speed around 118-122. I can say nothing but great things about the E-heads when used on the 455 block. With the way I've built this engine I'm sure this is what it would have been if I'd built either an HO or A SD & had reworked the heads back then. So I agree with 1971455HO in his assessment of his engine. If you want to make your HO or SD come alive you can rework the heads to the way they should have been or use a set of the aftermarket heads (Alum.) which will give your car the performance that it should have had from the factory.

[Formulajones]

If you guys want to talk about hotrodding stuff where anything goes, then by all means hands down I recommend aluminum heads and roller cams, and leave the 40 year old dinasour stuff to the resto freaks. But then why stop with a 40 year old ram air IV camshaft. Lets go modern lobes and put a roller in the darn thing and make those heads work for the money they cost. Why spend $2 grand on heads and put a blueprint 40 year old design camshaft in it? That's counter productive.

I built a nice pump gas 455 for my fathers GTO. Edelbrock heads ported by Kauffman, a custom spec hydraulic roller, 10:1 motor, RPM air gap, 950 HP, H beam rods and SRP pistons. Made 602 HP and 640 TQ, yanks the wheels and runs hard. Fun street car for several years.
That motor has since been pulled for a Bischoff built 572 cubic inch pontiac based off Kauffmans block. Same heads (albiet small for this motor now) and a solid roller spec'd by Bischoff. Another pump gas street engine that I'm told will hit the dyno around 800 HP and TQ next month.

[Formulajones]

Here's a shot of the goat running the old motor I put together.