Well, the 350 depending on it's internals could put about 500 to the flywheel but will have severe cooling problems ( no city driving ). The 454 would probably put out less stock but, being it's a former drag car, it's probably been hopped up a bit and would be a more reliable engine with less cooling problems. You could, if you wanted to, take the 454 to a shop and have it turned into a 468 and have a blower put on it, you'll put out mass hp's. the smallblock would take higher revvs better but the 454 should be able to take 8k. Really, I woulden't buy the car with the 350, not because it's a smallblock but because it's bored out a little to much with a blower to do anything more than ride on the highway, I'd have to park it in town if it were my car, would over heat going up my hill ( 3700ft above sea leval, highest point in prattsville ). You loose street reliabilty around 450 Horse, you may want to consider that also.