Denny, that would be a stock 400 I'm guessing it would have to be .30 over. How do you get over 400HP on that combo w/ a stock 400? I have aluminum heads w/2.02/1.60 valves and a holley 750cfm carb, edelbrock eps intake, and new 488.510 cam. Some insight on that issue would be great. I always thought that you need a real stout bottom end and fancy ass pistons and big bores to acheive that. Am I wrong? Can you get there w/ a stock motor and what I have for a top end? By the way the company is called gopher engine. And I have not found out about there warranty YET.