[cj847]

I would encourage you to embrace the digital age and go with an LS swap. The best way IMHO is to completely ignore the aftermarket. Get an LS and trans with < 250,000 miles and do not touch it (well ok you can replace a gasket only if it is visibly leaking). It was running when the truck was wrecked - it doesn't need to be gone thru, cleaned up, tinkered with, etc.

Just a reminder, the LS engine has been around since the 1990's. The average mechanic does not know how to work on a small block chevy. Much less adjust a carb.

Get a run of the mil 5.3 with 4L60E from a 4x4 vehicle. The issue with transfer case can be solved by using a passenger drop 241C from an 87-90 chevy truck or suburban.

Regarding cost - you could make this cost more than $10k by buying aftermarket stuff from JB conversions; Holley, etc, etc.
Don't waste that money. There is nothing wrong with the stock parts. Use 100% GM factory stuff and it all bolts together and works.