Ive searched and read too much to the point of being confused. . Have a o4. 5 600 cummins,and tow a 9,700# camper TT. . I have installed a set of gages and modified the air box and tube,looking for a muffler but want to get a module now! Being a daily driver + towing(love power+speed) there are three I like- Edge EZ,Banks 6gun,bully dog torque dog... ..... Anyone that have any of these modules give some input... . Thanks