I know it's not the best of motors, but I just scored a half ton short bed with a rebuilt 6.2, rebuilt 700r4 and t-case. It's an 86.

My thought is a Corp 14 and D-60 combo, sawzall the fenders and go 39.5's for a run around hauler.
Truck was in a wreck and is but ugly to start with.

What do I need to look out for with this motor?

I know very little but I had one problem with the only 6.2 I've owned. The vacuum pump (in the distributor location) aluminum drive gear went out at 310,000 miles and the little pieces ended up everywhere in the motor.

The main thing with that engine is regular maintenance.
Make sure you change the oil every 3,000 miles religiously and it should run a long time for you.
Also watch the temperature gauge, overheating those engines is not a good thing.

But treat them right and they will last a long time for you.