I'm thinking about putting a corvette servo, a .521 monster boost valve, and the gm repair kit (for full throttle 3/4) in my trannie (700-r4 90). It already has a crappy B&M shift improver in it (notice I didn't say shift kit ). I was wondering is a .521 a good idea or not? This is my every day driver, but I want it to be really neck breaking shifts. Right now I can chirp the tires 1/2 if I try, but I that's still not hard enough for my liking. I want them to break loose 2/3 too if I'm trying. I've read over all the different posts about dirs, they seem to be pretty easy if you have a day free and you want to spend the time. What's everyone think?

 

The .500 is more than enough. Put in the Trans-Go Performance Shift kit along with the .296 intermediate/reverse boost valve & the .500 main boost valve along with the Corvette servo. This will make your trans shift firm enough without breaking it.