1991 c1500 rear axle to 1987 r10

[Mmmiguel]

I want to see if I can switch 1991 transmission and rear axle on to a 1987 r10 5.7. I’m thinking it could fit but not sure what adjustments to make ?

 

[ali_c20]

Welcome from Austria. Post some pics.

Transmission is direct fit if both trucks have the same transmission.

Driveshaft length.
Axle width.
Spring perches.

That's my first guess what to look at.