had to have a driveshaft made (mine went missing along the highway). problem now is the yoke is for a 44 and I have a 35 rear end. Do I buy a new yoke of just the conversion seal?

Are there problems with running this mismatched pair?

 

When you say yoke are you referring to the one on the new shaft. 44s came with several size yokes, one being the same size as the 35 (1310). You can always run a bastard joint if it's different but you'll need to know the sizes and be prepaired for some really confused looks at the local auto parts counter.