Suregrip issues?

Your car and mine sound about the same, weight and horsepower wise. I don't have a brake however.(in my mopar), (I didn't realize that you race, thinking you may have just been told it was a suregrip).
I'm using a Detroit locker, and it works fine for what I'm doing. And yes, you can rebuild the clutch type. To be honest, in your place I would probably freshen the sure grip and sell it, put the proceeds towards a spool. The transbrake is the factor that would cause me to move to a spool, I use a spool in my car with a brake.

Edit: assuming an 8 3/4, now would be a good time to move up to a 35 spline spool and axles.