Why change the complete cat-back when the factory dual tailpipe system is already made of a 409 grade of stainless steel?#2 DOD18M = Moderate.The mufflers are made of a 409 grade of stainless steel as are the extension tube's. They are also mandrel bent to maximize exhaust flow.All hardware and exhaust clamps are included for a trouble free install *(ALL PARTS ARE AMERICAN MADE)This muffler retrofit is something that can be done by the casual mechanic & requires No welding at all. Install can be done in 2 hrs using air tools.There is no need to pay a "Muffler Shop" to do a job like this with a universal muffler and substandard aluminized tubing when you can get a complete Mufflex 409 SS tube kit that has been engineered to fit your truck without issues.And there is no need to purchase a complete "catback" when it is not necessary and not be able to have a muffler choice in what sound you want from your truck.