Asked this question 3 years ago, still looking for help. 2017 Tradesman 3500 reg cab , 8' box, 4WD, SRW with 6.4 & Auto trans. Factory rear leaf suspension has the back end jacked way up, hardly gives at all till you have 850 - 1000 lbs. in it and almost bottoms out with a 2000 lb. mini-bulk...