I'd just spend it how ever Brandon tells you too. anyone with a 83 like his knows what he's doing! 
the thing to remember is it will be a DD and he is fairly new to wheelin, might want to start without a locker just to get to know the characteristics of a lifted yota first. He could buy that runner, pull the detroit from the rear and put in an arb. I dunno..
Cuz, i had a "auborn" locker in my 89 chevy... ( mudd bogg days ) it pretty much made it posi right?
