Driveshaft Question

[stateamind]

Ok, so I have a 700r4 from a 92 1500 donor installed in my 71 c-10 shorty. Plan on using the driveshaft from the 92. I like the idea of bigger u-joints. I will have to get a couple inches cut out of it, but that's ok. My question revolves around the pinion yoke. I've seen them somewhere online before, but can't seem to find them again. I need one to match up with the bigger rear joint of the driveshaft. My 71 is smaller. Anyone know where I can find these? Or possibly an easier (cheaper?) way to get the 700r4 connected to the 71 rear? Thanks guys.