Swap F&R diff between 76 and 81 truck

[Zoomad75]

Depends on the t-case situation. The axles bolt in. The earlier front shaft should be the Saginaw style where you have individual saddles for the u-joint on the front output yoke. Also the rear shaft on the early one might be fixed yoke if it's a 205.

The front on the later truck will most likely have a flange style mount for the cv to the front output of the t-case. Also, if the later truck has a 208 it most likely is a slip yoke rear output.

But as long as the size of the u-joint is the same at the front and rear diffs as the axles you are pulling out you should be able to re-use the shafts.