8.75 Chrysler Early 3.73 Ring & Pinion

The 8.75 Chrysler Early 3.73 Ring and Pinion from Motive Gear is a performance-grade differential gearset engineered for Mopar 8.75-inch axles. This kit features a 3.73 gear ratio with 10-spline pinion geometry designed to work with the 742 differential case, delivering the balance between acceleration and highway cruising that serious Mopar builders demand for street, strip, and off-road applications.

The 3.73 ratio sits in the sweet spot for early Chrysler platforms—aggressive enough to improve launch performance and responsiveness off the line, yet highway-friendly for daily driving and cruise speeds. Motive Gear's precision manufacturing ensures proper tooth engagement and load distribution, critical factors that directly impact durability and efficiency under sustained acceleration or heavy load scenarios. The 10-spline pinion interface is standard for this class of differential, ensuring compatibility with OEM and performance driveshaft applications. This complete ring and pinion kit ships ready for installation into the 742 case.

This gearset is ideal for classic Chrysler, Dodge, and Plymouth owners building or rebuilding 8.75-inch axles for improved drivability. Whether upgrading from a worn original unit or installing fresh gearing during a restoration, the 3.73 ratio works well with both stock and mildly modified engines. Proper installation into a freshly serviced differential housing, paired with quality bearing preload and seal work, ensures years of dependable performance.

The Motive Gear 8.75 Early is recognized across the Mopar community as a cost-effective alternative to NOS units, offering modern manufacturing standards while maintaining factory specifications. Builders often select this ratio when seeking a reliable refresh without changing the overall character of the original platform.