I've had Detroits and other lunchbox lockers in the rears of other trucks - won't do that again. They're fine in the front assuming the hubs are selectable. I just put an eLocker (Eaton, not Harrop) in the rear of the '84 and love it. I'm spoiled now. I'll never do anything other than selectable in the rear.
Per @84T4R's question, I have new OME springs, shocks and greaseable shackles. They've got maybe 400 miles on them. They're still stiff. I was thinking the truck would not flex at all off-road. I was kinda shocked (pun not intended) how well the springs worked on the trail. All four corners stuffed - even made contact. Now, I'm not in as much of a hurry to pull leaves from the pack.