I don't know if it was on here or Planet but I had discussed building the same thing Billy. Use yokes at each end for ujoints, weld a yoke in place of our cups and a yoke to the end of the splined part of the CV shaft. The main issue would be binding when turning while flexing since the u-joint would be trying to go 2 directions I think but in theory it should work. Be real easy to replace ujoints too.