The key to making a 700-R4 live is in the correct adjustment of the TV cable, controlling the lockup and proper cooling. There are a lot of 700-R4s in fairly high horsepower Corvettes, and they last a long time. Properly installed and set up, a built R4 can take 500 HP (or better) all day long.

Check this site for info:
http://www.bowtieoverdrives.com