The 6.2 can be pricey to rebuild... Alot of times you will run into cracked heads and or block main webb cracks. This can increase the cost of a rebuild to rise or make it not worth doing. DSG Makes a stud gurdle for the 6.2 or you could build your own to help combat the lower end cracks.
Yours being an 82 should have a "red" block. These have a higher nickle content block and are less likely to crack. They also use the course thread injectors I beleave. If the block was good it is a good base to build from. If not your best bet is a 599 or 509 block. Those will have a 1 peice rear main which is less likely to leak. Thing is, for the cost of rebuilding a 6.2 you could normally find a running 6.2 to swap in for less cash. Also check out sites like government liquidation were you can buy Humvee take outs real cheap. Or there are places like teds trucks and stuff that sell inspected good humvee take outs for a bit more cash. The problem is a good rebuild and upgrade of a 6.2 will put you into cummins price range. I don't know about your area but here a running 6bt will bring between 1000 to 2500. A running 4bt will run you 2000 to 2500. But the cost rises as you ad in adapters and transmissions.
I went 6.2 cause they are cheap and good on MPG. If I had the money I would of gone 4bt as it is just a stouter motor. It is kinda cool to have a 6.2 that runs well as alot of people discount these motors but they are not and never will be as rugged as a cummins, 7.3,6.9,.........