Huge 4-wheel drive problems Front drive shaft

[tai6mai9shu]

I have a 84 gmc, i was replacing the u-joints in the front drive shaft and i got the two by the transfer case out and the new ones put back in and then i went to put the one at the end of the drive shaft in and i put the center peice in and then i slid the caps on andthey went right in with no hammer no nothing, and the u-joint that both the parts stores gave me had outside snap rings. well thats all fine and dandy with the part of the u-joint that is mounted into the knuckle type thing on the front pumpkin cause that doesnt need the clips and has two little ears that hold the caps on, so then i go to put the outside snap rings on the u-joint that is actually on the shaft and they sit flush with no room for the caps. so i went back to the parts store and told them i need the universal with the inside snap rings and they say that they dont make one? so i have no idea what im going to do for a front u-joint for the front of the front drive shaft?????????? everyone at the parts store says that someone must have placed a different front yoke on the shaft cause the u-joints are not matching up, wondering if the stock yoke spines will match up so maybe i can put the stock front yoke back on it and then place the right u joint in there. any way i can find out how many splines the front yoke for the front drive shaft has?
Thanks any help would be greatly appreciated. Thanks