I had a "Burb with a 6.2. Stone reliable, mileage as described or a bit more, no issues with the tranny, but I was not a heavy puller. I was also in the Army during those years and the 6.2 CUCV (Blazer/Pickups) were very relaible and tough.

OTOH, I had a 6.5 Turbo that was a massive POS. Fuel injection pump issues would prevent hot starts and the pump was twice the price of a 6.2. Avoid the 6.5 in my opinion.

A good reliable engine, the 6.2. You can find remanned ones at Government auctions for a reasonable price.