I have always heard that the Ford 8.8's were junk from fellow destruction derby drivers. I personally have blown up two of them in the derby arena that were under 80's Ford Crown Vic's. The spider gears were welded in both of these and the heat from welding could have made the gears brittle and subject to failure though. Most guys say swap for a 9". Maybe the ones from the Exploders and Rangers are stronger.
I am interested in the cheap price and disc brakes you get with this swap. It's still gonna be about the same as putting a B body 8 3/4 in.