Depends on what you have done to the trans, but as long as you keep it on street tires and on the street (where you have no traction) you will probably be fine. The 8 3/4 will also probably be fine on street tires, on the street. The problem is when you put on sticky tires (drag radials) and go to a prepped race track....I have seen too many street cars try to go racing and blowup rears/transmissions lately....Don't really want to see more.
If you want to tread that street car/race car line, my suggestion would be to put a dana or 9" under the rear before you hit it hard at the race track. I'm not sure what I would do with the trans... I personally run a manual valvebody 727 with a 8" converter in my Barracuda, and it handles street driving and racing quite well. With a stroked 360 (408), my car makes close to the power you want, only it runs low 10's, not 11's.
