I recently installed a saginaw 2-groove 4-spd in my 51 chevy 235. the slip joint on the tail shaft and the tail shaft have finer grooves than the three speed did and I couldn't use the slip joint from the 3-speed and the one on the 4-speed looked like it had the clutch popped on it one to many times as the splined grooves in the slip-joint were slightly twisted and made it hard to get the slip-joint all the way on the transmission tail shaft!! I did get it on and it works OK but I would like to get a new one. question to ya'll is where do I find a new slip joint??? Thank you.. AG-Pilot