2014 Silverado 1500 High Country transmissionmfrcode : 6L80, With RPO Code KNP (Heavy Duty Transmission Cooling System), Transmission to Radiator and Auxiliary Cooler. 2014 Silverado 1500 LTZ transmissionmfrcode : 6L80, With RPO Code KNP (Heavy Duty Transmission Cooling System), Transmission to Radiator and Auxiliary Cooler.
