Power limits of stock 360 block and crank.

They'll take what they take. The weak spots are the crank (factory is cast), and the mains. The factory crank can take a lot of abuse but it's only so good. If this is to be a serious deal (500+hp), I'd recommend adding a forged crank to it. In either case internally balance it well, run the lightest rod and pistons you can, and depending on your plans, possibly replace the #1-4 main caps with 2-bolt Program caps and studs. At that point you're pretty much done doing what you can. IMO if you need to do more - you really need a better block. Doing that will hold 600+ for a while. You could also add some hard blok depending on what you're doing. For a street car I don't like taking away cooling capacity.