I just got my dads 1976 trans am with a 455. I want to start replacing parts, and get some more hp. I was wondering where i should start.

put you some headers on it and check with eldabrock carb and intake for more power. you could put nitric in it.

TransAmMan,

If that is an original 455 car (came from Pontiac with that specific engine in it), I would remove the engine AND transmission, slide them under a bench covered in a moisture "proof" cover and store them for "posterity". '76 455 cars are pretty rare. The '76 455 is a turd as far as performance goes, but the novelty is "special". No matter what you decide, I advise against making any changes that can't be undone. No cutting or drilling on the body, please. This car WILL have collector value in the future, as long as it is relatively unmolested. Anything you remove, label and store for reinstallation, even if you won't be the one.

Once the original engine and trans are safely stored, get a 400 block and get "started". By stroking a 400 to 461, you get "the best of both worlds". That is, the strength of the 400 block (physically stronger than a 455 block) and the displacement/performance of the 455. There are other advantages as well.

TH350 (what's in there now) isn't up to the task of a high-powered Pontiac. Pontiac put them in because TH400 wouldn't fit with the catalyst in place and the "smogger" engines didn't make enough power for them to be a liability. TH400 is the only OEM trans that CAN stand up behind a well-done Pontiac. Torque output far exceeds small blocks, and significantly exceeds big blocks (Chevys).

The 6H heads have HUGE (124 CC) combustion chambers, making them poor candidates for a good performer. If iron heads are in the "future", 6X is a good place to start for the larger engine. Edelbrock, KRE, AllPontiac and Jim Samson all supply aftermarket aluminum heads that are VERY good.

Comp has the cam issue nailed. The XE grinds are superior to any other we've ever tried in "pump gas" engines. Flat tappet hydraulics and solids, hydraulic and solid rollers are all avalable. Flat hydraulics are the "norm" (as wiht most streeters). Flat solids are regaining popularity as valve train parts are more refined. We avoid hydraulic rollers, as the "retro-fit" lifters can be problematic. Solid rollers are the best. Modern parts make them a viable street system.

I would get Jim Hand's book "How to Build Max-performance Pontiac V8s", published by SA Designs, and get "educated" on the current approach to building a strong Injun. 600 HP on 93 octane is straight-forward. It's not "cheap", but neither is any other 600 HP "pump gas" engine. We have guys running deep into the 10s in "drivers" weighing in over 3,500. You don't need to start there, but it IS available, so plan accordingly.

Scrapper,

Adding headers will help, you're correct, but only "real" ones. The three-tube cheapies don't make any more power than the log manifolds. The "HO" or "Ram Air" manifolds make more power than cheap headers. GOOD (Hooker, Mad Dog, Doug's, etc.) headers make a world of difference. CERTAIN Edelbrock intakes will help, too. The factory iron intake on these engines is actually superior to "Performer" for power production and efficiency. At the higher preformance levels, Torker, T-2 and RPM have "their place". Pontiacs don't have nearly as poorly designed factory manifolds as most "OEM" engines. And the Edelbrock carbs are useless on a Pontiac. They're only marginally useful on 350 Chevy, which they're "intended" for. Q-Jet is the best street carb, but must be built by a knowledgeable Q-Jet builder. "Quadra-Flood" and "Quadra-Junk" are statements coming from someone that is NOT a good Q-Jet builder.

For sheer power production, you just can't beat a good Holley. We get ours from AED.

Jim