U-joint?

Do you think a couple tac welds would be a good assurance, til I can get a replacement? Does and one hafeca sugestion as to where I can get a new one? I have a 833 4spd, with a 8.75 rear (it's a Challenger put I would an a body would be the same).
Welding will cause the grease to burn out of the caps. I believe the yoke would be the same from another 4 speed shaft. The shafts are different.