Upgrading to larger wheels and tires on your 2006-2007 GM 2500HD/3500HD can lead to a noticeable loss of power when driving or towing. Aftermarket axle gears are the ideal solution to restore your truck's power and efficiency. Our selection of OEM-style, precision-crafted rear gears ensure like-new performance. Whether you need a single gear or a complete set, you’ll find the perfect fit at Alligator Performance to get your truck running at its best. Equip your gears with a quality Install Kits to ensure they run flawlessly. GM Duramax Fitments: 2006, 2007 GM 6.6L Duramax.Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali.Some exceptions apply, please see individual product pages for specific fitments.