Ring & Pinion Ford 9in 3.89

The Ring & Pinion Ford 9in 3.89 by ALLSTAR PERFORMANCE is a precision gear set designed for high-performance rear axle assemblies in Ford 9-inch differentials. This complete kit is tailored for builders and enthusiasts who prioritize reliable power transfer and optimal acceleration characteristics. The 3.89 gear ratio provides a balance between speed and torque, making it suitable for various performance applications.

This ring and pinion set is engineered to ensure secure engagement with compatible driveline components and carrier assemblies. The 3.89:1 ratio indicates that the pinion gear rotates 3.89 times for each revolution of the ring gear, effectively lowering input speed while multiplying torque output to the wheels. ALLSTAR PERFORMANCE gears are manufactured with premium materials and precise heat-treatment processes to enhance durability and extend service life.

This kit is ideal for builders upgrading factory Ford 9-inch rear ends or those assembling custom differentials for muscle cars and performance trucks. Proper installation with quality differential fluid and adherence to backlash specifications will ensure maximum efficiency and reliability. The 3.89 ratio is particularly beneficial for applications requiring responsive gear reduction without excessive RPM climbing.