Rowing these gears is the best way to enjoy your car if you ask me. I changed to a 833 (18spline)couple of years ago resulting in breaking teeth of the gears, ruining clutches while trying different setups but all without any real luck. This all was with my street/strip challenger with 528 Hemi running 10's.

In the end bite the bullet and got myself a tubechassis car and bought a GForce 4-speed and custom AC clutch setup to put behind the same pumpgas street engine.
Results; 8,9's and it's still alive

Can't improve the funfactor