Motive Gear G80390 Differential Ring and Pinion, 3.90 Ratio, GM 7.75" IRS, Performance Gear, Replaces 69-0461-1, Compatible with 2004-2006 Pontiac GTO

This install easily and functions well, its a bit noisy and locks solid when you hit the throttle. Beware that when locked under hard acceleration you can possibly spin out but that's the name of the beast. I love it....