Anyone have read or have any idea of what the max torque before you turn the independent suspention into a salted pretzel? I am Dyno'd at 505 ft/lbs and think slicks will twist the rear. I have yet to find an article on the limits of the 03's rear indy.
For all my data collecting, once you reach 500 hp/tq you are playing with fire if you don't upgrade from clutch to diff. cover. There are exceptions for those under and above 500... but if you are indeed at 500rwtq, then I'd look at new halfshafts, rear dif brace, and IRS bushings. Milage and opinions may vary...