I put 225K on a 6.2 in an 84 3500 SRW. I didn't replace anything other than starters and wiring in a manual glow plug system. Other than that, it just ran. So for me it worked, as shown others hated that motor.
I have seen crate 6.5 motors for sale at Army Navy stores (the big ones) or you might catch them yourself at DRMO military auctions. The 6.5 replaced the 6.2 in the Humvee. There are many unused 6.5's sitting on crates. If you could find one I would use that. If you really want a 6.2 try to find one that was meant for a 3500 series pickup. They had a different intake and I think were called J series 6.2L. I am pulling this from memory and its been awhile since I have messed with these motors so varify. You might also just buy a Cutvee (military pickups they were 85-87 3500's with some additional springs) I think they were considered a ton and a quarter if I remember right. Unless already converted they would be 24V but these pickups had the more HD 6.2L I am referring to. You buy these pretty cheap. Buy it part it and use the running gear in your pickup. It will bolt right up.
