What engine are you running? At least one of the adapters to mate a GM automatic to the 235/261 engine is a little flaky, but the suggestion about the 700R4 is a good one. One little suggestion- - - - -get your transmission builder to install the Corvette clutch drum in the overdrive section- - - -it's got a couple more clutch plates for better lockup and no slip in OD. Stay FAR away from any modification with the words "shift kit" in the name- - - -they're a recipie for disaster!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!