This may be a dumb question, but how can I tell if it's an LMM? I just bought my truck, it's a 4x2 Dually and brand new as of a week ago. I will be towing a Take 3 auto transport trailer (3 cars) behind the rig, so that's why I'm interested in the exhaust brake. Any info people could share about an exhaust brake or better brakes than stock would be greatly appreciated!:drink