Another option to building one, is sourcing one from the West coast and S. West, we don't salt our roads out here, so rusted out frames aren't that common. A 2wd drive frame from the same gen (79-83) era is virtually the same, you would only have to modify the front for the leaf springs, same as doing an SAS on the IFS frames.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed