I think all TS models are built on the 3500 chassis. We have a 2014 (2013 chassis)TS, 3.0l on the 3500. Drives nice and gets 17-18 mpg. No experience with the 2.1l but reports are that it gets better mileage.
Dave, Dale, and Poppy the Soft Coated Wheaten Terrier
2014 Pleasure Way Plateau TS