Regear the differential in your 2004.5-2005 Chevy/GMC 6.6L LLY Duramax with an all-in-one kit. The races, seals, bearings, and ring & pinion set you need for installation are included with these kits. To suit your particular requirement, these kits are offered in a vast array of gear ratios to suit your vehicle needs, gear ratio, and tire sizes. Get high-quality brands like Yukon Gear & Axle and Nitro Gear & Axle.