GDP 2017-2019 6.6L Duramax Custom T87 Transmission Tuning Package Fuel System Accessories 2001-2007 Duramax 6.6L LBZ/LLY/LB7 Some aftermarket pulleys will switch

Some aftermarket pulleys will switch to a different length bolt and spacer which will not work with the our billet pulley

Emissions Level 1 Level 2 Level 3 Level 4 Level 5 ON 0HP 50HP 75HP 100HP OFF 0HP 50HP

proven calibration that eliminates throttle lag and delivers raw drivability gains right where you need them

For pick-up models only

Preset 15-18 psi

GDP 2017-2019 6.6L Duramax Custom T87 Transmission Tuning Package Fuel System Accessories 2001-2007 Duramax 6.6L LBZ/LLY/LB7 Some aftermarket pulleys will switchGDP 2017 2019 6. 6L Duramax Custom T87 Transmission Tuning Package Package Includes: HP Tuners MPVI4 (Optional) 4 HP Tuners Tuning Credits (Optional) GDP Transmission Tune Note An HP Tuners MPVI4 & 4 Tuning credits are required to load the transmission tune into the vehicle