I have been calling around to local machine shops about my ls build lately. last week I got into a discussion with a guy at a machine shop who said the ls stock crank is only good to 500 hp. Is this true? I plan on a build of the upper 400 hp. then it will be sprayed with a 150 shot rarely only when I really want some extra power. The nitrous wont be used all the time. This is a street car car. Do you guys think the factory crank is enough? or will it crack under pressure?
the LS1 factory crank is perfectly fine up to 900 to 1000 hp. you will be perfectly fine. now the ls1 bottom end (factory rods/pistons) are only good to 500 hp. if this guy is telling you the crank is also than hes an idiot.
The factory crank/block are usually more than enough for your average street car build, that's usually one of the last things on the list to worry about. However, your stock internals will definitely be a concern