750,
I run a shortened 9" with new version Tru-Trac with 31 splines and it works great. No clutches to wear out and no special gear oils. The helix gears are engaged with gravity "throw-out" races. I still get some "chirp" on quick tight corners...maybe doesn't disengage fully unless you slow down.
I push maybe 350 hp to the rear and am happy with the traction although I'm still breaking things in (engine, clutch, my juevos, etc.)
Try looking at Currie Enterprises in Anaheim Ca $450 w/$500 installation and setup.
scratch
