Expect a lot of opinions, both ways.
The photo is of my stock Dana 36, an early design that came on all '84s. A tooth broke off of the pinion gear and wedged between it and the ring, which broke the case. The ring gear had only some nicks. The diffy was properly set up and maintained, despite one 'expert' opinion to the contrary.
The newer Dana 36 case is a bit stronger, but not as beefy as the Dana 44. The 44 diffys are not too hard to find, but the rear covers, with the crossmember bracket, are. Those available are not cheap!
My expert claims that the newer design, which had the internals and the case cryogenically treated, will withstand my power, which is a bit above what you expect. I am running street radials, 315.35x17", which spin at will with a 3.54 ratio. They are my 'circuit breaker'. I opted for a lower ratio, which gives more tooth contact; two, vs one in my broken 3.73.
Great gear oil, non-synthetic yields better protection, unless running long events, at high speeds, which greatly heat the lube. In that case, a synthetic is probably a better choice of lube. I considered the extra heat from my 3" exhaust, which runs right under the diffy; then chose
Lucas Heavy Duty 85/140 gear oil.
www.lucasoil.com/
A great shop can give you specifics, as tooth contact depth and area varies not only with ratio, but by manufacturer.
Abuse, as noted above? << all bets are off.
Note that experts and not, all over the country, claim both ways. Some claim neither diffy will stand the power, no matter what. Others aver that either, properly done, will do fine.
Been there....... Never found a reasonable 44 package, hence, my choice.
