I plate and insure the following:
1982 K30 3+3 long box 454 SM465/NP205, Dana 60/14bff 3.73's, 36x12.50x16.5 TSL's
1985 K5 350, TH350/NP208, 10 bolt/10 bolt, 3.08's, 31x10.5x15 BFG All Terrains
1987 V10 long box 350 TBI, SM465/NP208, 10 bolt/10 bolt, 3.42's, 31x10.5x15 BFG Mud Terrains
1988 V10 Suburban (heavily modded) 350 TBI, SM465/NP208 Dana 44/14bff, 4.10's, 315/70R17 BFG All Terrains
1990 K5 350 TBI SM465/NP203/NP205 Dana 60/14bff, 4.56's 325/85R16 Michelin XML's
1995 Carpenter 71 passenger school bus.
The 1985 has a blown engine in it right now. I am not sure if I want to replace it, or just haul it to iron. I drove that the most last summer. I just put an engine back into my '90 K5, and have now been driving it the most. I would say you definitely want EFI. I have grown to hate carburetors. Other than the poor gas mileage, I love DD'ing the odd hunks of ****. I would also recommend an overdrive if you go automatic, or an SM465. Some people seem to not like the SM465's. I love them. If I put an engine in the '85 K5, and keep it on the road, it will get an SM465 when the automatic lets go. If you do go with an SM465, the hydraulic clutch does make it easier on your left leg.
Martin