Suggest taking to a reputable builder instead of monkeying around with it yourself. (understand I used to own a transmission shop) In Houstion there used to be six speeds inc. with a guy named Honeycut but word awhile back on ls1tech was they may have stiffed several people. Search ls1tech for a good builder. There has to be some in Houston. There are several up here in DFW (Standard Transmission and Gear, Texas Drivetrain Performance) This is who several racers (Patterson) have used recently with excellent results-he has also built an AI car which you can see on their website so I would just call them. Tell them you are a racer and see what they can do to help you. Ship it to them and pick it up here or have someone pick it up to install at the track.
http://www.dederichsmotorsports.com/

Nice dyno!