Dynatrac-ProRock-XD60-IFS-for-GM-Trucks-1 Dynatrac™ introduces the missing link in GM IFS truck drivetrain: the ProRock XD60-GM-IFS™ for the ultimate upgrade in front axle strength and durability. Developed for military applications, the ProRock XD60-GM-IFS provides unmatched strength and durability for 2007 and newer GM 2500 HD 4x4 trucks with Duramax and Allison transmission. The core of the new Dynatrac ProRock XD60-GM-IFS is high-strength nodular iron center section. The XD60-GM-IFS features exclusive larger carrier and pinion bearings for even more strength. It uses a massive 10.1-inch ring gear compared to the factory 9.25-inch gear. Even more significant to durability, though, Dynatrac designed the new center section for world-class rigidity, increasing the stability of critical tolerances during high stress. This nearly eliminates the chance of gear failure caused by axle housing deflection. The ProRock XD60-GM-IFS features optimal cast-in bosses for air locker and electric locker connections, and the mounting points for the housing are an integral part of the casting. In addition to these engineering advancements in the center section, the Dynatrac XD60-GM-IFS features an all-new structurally-integrated differential cover designed to add strength to the overall housing. The cover is made from nodular iron, attaches with 7/16-inch Grade 9 fasteners and a captured O-ring seal. The Dynatrac ProRock XD60-GM-IFS comes with 35-spline or 40-spline 4340 inner axleshafts and supports stock, 934 or Series-30 CV flanges. The ProRock XD60-GM-IFS accepts a full range of differentials, including air lockers and electric lockers. Gear ratios are available from 3.54:1 to 5.38:1.