my truck has stock sticks no problem just did a oil test fuel was <0.5 5K on the oil and Dr Performance. towed 18K with TST and Dr Performance the other day running 80 up the hills no down shift (OD) EGTs did not go over 1400. TST only when you lug the motor smoke is pretty heavy turn the Dr Performance on smokes less trailer loves it and so do I dont have to spend all day washing soot off the trailer. now no load on the truck TST on 7/8 truck pulls good. but you want some power put TST on 3/2 Dr. Performance on tow now you got some power. but the most fun I have with the truck is when towing and my buddy has a 555 dodge and I pass someone going up hill at 90 he cant belive it, either can the car next to you. I am a happy with Dr Performance. Buy new you then know what you are getting there most update programs