The local driveshaft guy that all the local racers used has retired. He understood critical speed and asked all the "critical questions" before he would build you a shaft. I had my last driveshaft built by Strange but I still have the driveshaft that Dave at C&U made for my 5-speed set-up. Hope you come up with the solution that you can have a stress free build. I'm sure there are racers out there with similar builds that live and run fast.

Gus