Converting to 4WD

[GmtGmt]

i have plans for building a Flat bed Hauler out of my newly purchased 2WD 86 Crew Cab.

but i would really like to have it converted to 4WD because i will proberly come into situations where i would need it with this heavy truck like wet grass, mud or snow

but i would like to keep the the stock 2wd hight maby even lower it some
so going to a solid front axle Dana 60 or 70 is proberly out of the question

so i thinking the K3500 88-98 trucks had Indy Front suspension with CV Half Shafts, could i take the complete suspension and move it over to my 86 chassie or would i be better of buying a 88-89 Chassie and mod the cab mounts for my cab? because then i would also have ABS brakes

also building a frame from the ground up has also been a though

whats your thoughs on this would i even need the 4wd?