steering shaft and u joints and rag joints and double D and......

[padresag]

the nbr of splines may designate what series of vehicle it belongs to. 30 splines is 1/2t, 26 spline is 3/4t and 40 1t. I needed a new str. box for mine years back and found that my old 36 spline box had come from a 76 3/4t 4 x 4 suburban. they had sent me a 30 spline first.
all of the str boxes should be interchangeable as long as you have the correct rag joint to go with it. that is my conclusion which may be wrong but stands to reason
ron