Hello everyone. I have a 2012 Silverado LTZ with a 6 speed and 3.42 gear ratios. I want to change ratios for towing and more oomp while driving. My current axle has the JL4(active Brake Control) option and I have found several local 10 bolt axles that are already pulled from the correct year donor vehicle but I dont know if they had the JL4 option. My question is- is there anyway to visually tell if a used rear axle was used with the JL4 option? - since the donor vehicle is not available to check the option code list. Thanks in advance for any information you can give.