Here is another online site for the 700r4 .

http://www.700r4.com/

They have a fair amount of information to help you understand what they are doing and why. The higher stages handle 630hp/torque.

Best part is all the information and other parts needed to hook it up are avialable on the site.

I have yet to buy anything from them but was thinking of getting a Level 3 to go behind the 500 cadillac going in my 85 caprice. Still haven't checked with local shops yet, and I went back to college again so I don't have the money anyway.