One other concern would be getting a transmission yoke to fit the TH400 series 27 or 30 splines or whatever it is and be 1410 / 1460 series on the U joint. You will find that those yokes are much heavier and are for larger diameter shafts with 10 splines or so. Also they are not made as a slip yoke to fit like a car uses but rather are like a midship stub uses. I doubt anything is readliy available.
Frankly I don't think this is a good idea.
