700r4 install driveshaft ?

[canso]

I have installed a 700r4. I have a driveshaft off of a 83 Chev vehicle that is the correct lenghth. The newer drive shaft has larger caps on the u joints. Where the drive shaft connects to the tranny I have no problem. Where the drive shaft connects to the rearend, the caps are smaller on the diff yoke. I am told there is a standard cross over u joint for this. Instead of using a cross over u joint I would like to change the yoke on the front of the diff to one with the larger caps. I need to figure out what to get a yoke off of that will work. I am wondering if anyone has been through this. My diff is a 72 12bolt. Thanks