As said you need a "combo" ujoint of which several brands are available, for the rear. The "cross" will be 2&5/8 wide one way to fit the shaft and 2&1/8" wide the other way to fit the pinion yoke. After installing it move it back and forth & if it ain't smooth/with no binding then whack the ears with a drift/bfh till it's corrected. The "ears" are the 2 metal pieces on the shaft that connect the 2 holes in the driveshaft to the rest of the shaft. Set the shaft on the ground horizontle supported underneath it along its' length so the ujoint/yoke on the end is an inch or so off the ground then with one ear at 12 0'clock whack it then turn it 180 & whack the other ear then see if it is free & repeat as needed. Before you get to this point, when first installing it, driving the ujoint in with a hammer works better than compressing it with a vise surprisingly as a hammer is always my last choice on most situations. On the front trans yoke same deal, want it free in both planes of movement but sounds like you are good there & this is a pig change only in the rear