Not sure of exact hp/tq figures ,have only just unwrapped motor from box so far!
sitting in auw of it at mo! But your estimate of 500/500 should be close.
Steelie Gears( supplier in nz) recommends a trac loc diff, which is different again to tru trac and detroit locker? Anyone had experience with that design?
I'll have a search for diff technic's and see what they can supply/cost's.
Weight of car would also speed up wear of unit too? how much do nascar's weigh?