How in the hell did i miss that post..... Let me ask this, does anyone besides me actually live in Japan? I know theres at least two others, so please speak up. First of all, there is no horsepower regulation. PERIOD. Nothing that says a Japanese car manufacturer has to limit their horsepower. There's the mystical gentleman's agreement, and thats it. Secondly, the valves are exactly the same size on both heads. You can almost use the 2jz cams in the 1jz except you have to mill down the front journal .1 or something. All of the GTE heads have ports that are angled for the TT manifolds and the heads flow almost the exact same. My 1jz revs pretty damn fast, but there are some 2JZ Supras around the sound like motorcycles.