The block will handle gobs and gobs of nitrous. It's the intake and fuel supply that are the major concern. A large shot (significantly) increases the chances of my blowing a hole in the firewall-side of my intake manifold. Plus there's the risk of burning a hole in a piston or folding a connecting rod in half. Yadda, yadda, small concerns. I've heard of people using a dual stage nitrous kit on stock mod motors to run a larger shot.