1991 crew cab 4x4 hauler build

[Levi L]

I just got a new to me V3500 Crew Cab 98k miles 5.7 4L80E 205 SRW it has the good clip silverado clip but base interior. I know the history pretty good, as I am the 3rd owner in the Service DEPT at the Dealership i work. Its big and grey, and is know as "the Whale". I'm a GM service advisor (former GM/ASE Master Tech) , plans included NNBS seat swap front and rear, and 6.0 ls(4bt???), and maybe a DRW conversion and a 2.5 inch lift. Maybe some 285/75R16 BFG AT if I stay SWR. 255/85r16 if i go DRW.