I installed a Magnaflow 15565 (took it off my 2012 1500) yesterday on my 2014 crew cab 1500 with 5.8 motor. It installed with no problem at all, everything matched up except on the 2012 there was a extra hanger. I drove the truck around maybe 50 miles total yesterday after the install and everything seemed to work just fine, still dropped into V4 and the mileage seemed to be about the same. So for everyone wondering if the old system will fit and work it will.