differential swap

[jwpa2]

Hey guys or gals, I recently swapped out my Differential's from 1984 GMC 1/2 ton to 1985 suburban 3/4 ton axle's and have noticed the driveshaft U-joint is not correct, the half ton U-joint that the cap is smaller then the 3/4 ton axle yoke and was wondering if any of you all had ran into this and what U-joint you may have used for that. Thank you.

[Captkaos]

Assuming you mean you swapped complete axle assemblies as differentials from a 1/2 and 3/4 wont interchange.  A 1/2 ton axle would be a 10bolt and will definitely have a different u-joint than a 3/4 ton which would be a 14 bolt.  10 bolt = 1310 Ujoint vs 14 bolt = 1350.  You could get a 1310/1350 conversion u-joint, but what was the reasoning behind the swap.