Sounds like it had a van rear axle. They do make a combination u-joint for just about any application, NAPA is the place to go, they can figure out what you need quicker than anyone. And instead of having your wheels "drilled" (I REALLLLLY dont think that's such a good idea) you should pop the rear end cover off, take the crosspin out, knock the axleshafts in a little and pop the c-clips off the ends of the axles. This will let you swap them out with the right ones and eliminate the need to drill your wheels. The problem with swapping the yoke is getting it too tight, or too loose, throwing off the pinion bearing preload. Not so much messing up the mesh pattern. If you do undertake that be sure to use red high strength thread locker on the pinion nut, use a new pinion nut as well, and tighten the pinion nut to around 20 inch pounds of rotational torque. It should spin easily with your fingers but when you let go stop immediately. You can't really set pinion bearing preload with the carrier in the axle so you may be ahead of the game just getting a combination u-joint.
