Billet Rocker Arm Valve Bridge Set 01-16 GM 6.6L Duramax XDPThe XDP Billet Rocker Arm Valve Bridge Set XD384 will greatly improve the factory valvetrain in your modified 2001 2016 GM 6. 6L Duramax. The OE rocker arm bridges in your valvetrain were designed for stock output levels. Once modified, your Duramax engine can quickly produce more stress and load than the factory rocker arm bridges were made to handle. The XDP rocker arm bridges are CNC machined out of hardened 4140 chromoly for extreme strength. Each