Ford has a similar guide: https://www.fleet.ford.com/towing-guides/All manufactures should provide this kind of site. Ram will tell you vin specific Ram Towing specs. We had a 2003 DWR cc 5.9 Ram for 400,000 miles and loved it. Then we went to a '14 6.7 CTD DRW CC 4.10 Aisin trans Ram (39890# towing capacity, 4800# payload); the difference was night and day. Go as big as afford you'll never regret having too much truck, ever.