Soon To be NEw TO BBC

Ok, so I have a 78 trans am, i have a pontiac 455 short block I was planning to build for it, but today I happened to come across a 454 that Im likely to buy tomorrow. Its a 1990 454 ss. Its complete oil pan to intake, with powersteering alternator and all. It is missing the throttlebody, but im thinking ill go with carburetor anyways. Anyhow before I buy it thought Id ask a few questions about this motor? I was told it had 6.135" dimple rods. Is this stock? If not are they better? Whats the best cam to put in this motor? I would like to attempt getting between 450 and 600 hp out of it. Im gunna try to get by without machining it, i am planning to rering it, and make some upgrades.... any tips suggestions on what I need let me know please. Also I have a th400 transmission here.. that i got for the 455, what do i need to bolt it up to the 454? Thanks. K.C.

doing a 495 out of a 455 pontiac right know . a 455 is not the same in any way to bbc so you need to buy a trans adapter plate or a chevy 400 trans to bolt to the chevy bolt pattern. dimple rods do not mean much they do not add power the engine will not care same with what the pistons or crank are made of only when you add power adders and RPMs . the mark 5 dimple rods are not better then the old truck or thumb rods hard to say what you have for a engine before you can say what your going to get for hp realistic would be 400 hp no machine work ? need a hell of lot more info on the engine. i am thinking you trying to do this on the cheap? seldom do big HP numbers and cheap go hand in hand

Don't discount a poncho motor.

One of their great advantages: they perform just fine with factory exhaust manifolds. Headers give little if any gain. They make loads of torque.

I'd advise you do a cost analysis before you make a decision.

IMO--
firebird77clone makes a good point!!

If you go with the Chevy motor, what are your plansfor the 455?