How much hp/torq will an OEM 833 4sp and 8 3/4 take?

Just don't put an A833 overdrive in it! The od gear is pretty weak. I took two of 'em out like nothing,with my 367.
And the CFII will destroy stuff if you start sidestepping it, at peak torque,lol.
I think YR is on the right track, in post #14.
Pick an R&P set with lotsa teeth on the pinion.The more the better.