Seems the stock short block can handle about 400 - 450 hp. Above that you would need pistons for more CR as well extra strength and for the price might as well go for better rods. As for block seems like above 600 hp the block becomes questionable. As for the crank Im sure theres people running 600 plus hp on stock one but if I was building the engine if I was looking to build 500 plus hp I'd go aftermarket.
