I think my 8 ¾ housing is toast.

I had the same problems with running the caltracs with 8.75. I went to the Moser MO875 and it fixed that problem. It is a very nice piece, but if you start making over 550 rear wheel HP it will create another problem.(Then you are going to start breaking the gears and the transmission). Been there and done that. I run low 10s so I went to a DANA.