[vectorit]

The 4x4 stuff in a 1972 burb, is the same as what's in a PU.
What are you really looking for?
Suspension, axle, springs, transfer case questions?

Mechanical stuff for this, has a huge cross reference so finding parts is actually pretty easy if you are staying OE. The big parts houses mentioned, mainly carry the small perishable parts like bushings and maybe a bracket or two.

Lots of the 4x4 stuff, or back half of the drive train is salvage parts.
Unless you want to build new drive shafts, or buy new U-joints then you are best suited to find a specialist in your area for the shafts. The U joints and front shaft joint, are best found from 4x4 specialists that cater to Dana equipment. Since Dana Spicer was the main supplier of these parts.