Performance Valve Springs and Retainer Kit Cummins 6.7 Fits both upper and lower

Fits both upper and lower connection

Supports Up To 750HP

Even in mild builds

this unit is built to meet OEM specifications

This can be hard on a turbo and motor and is not recommended

Performance Valve Springs and Retainer Kit Cummins 6.7 Fits both upper and lowerThe XDP Performance Valve Springs and Retainer Kit XD386 are a perfect upgrade for your modified 2001 2016 GM 6. 6L Duramax. Camshaft upgrades and other modifications that increase boost require more valve control. The XDP Performance Valve Spring feature a conical design for better valve control than a standard straight spring. The conical design also allows for smaller and lighter spring retainers. Each spring undergoes a stress relief process and