Tranny/Rear End

I'm looking for a shift kit for my Oldsmobile. I post here b/c this is where I used to post when I had my z-28, and got a lot of help. It's a 3 speed th350. I need to rebuild it b/c I smoked it on the way home blowing some doors off. I put a lot of $ into the motor/heads a while back adn got some serious horse out of the 350 (which is rated somewhere around 320 stock) So I wanted to know if anyone had luck with shift kits, or preformance rebuild kits. Also, i wanted to know of a good posi/spool I could use. It's more or less a daily car, i drive it a lot, so i dunno about the spool.... Links, reviews, anything would be cool....

i have a transgo shift kit in my 700r4 and it works great i know they make those for your trannys too...and for posi unit id say eaton..

Transgo is the best and what size rear do you have?. Auburn and Eaton both make quality rears though.