i have been towing awhile comparing both and let me tell you the tst is the way to go if you want to tow. lower egts and the TQ let me hold almost every hill while grossing 30K. the diablo would make me back out b/c of egts. i set the tst at 4-0 and its real easy on the clutch b/c it fuels real slow. however, the diablo makes the engine run much smoother. now running empty and having fun i set the tst at 5-3 and powerpuck at 90[guitar]. this is a great stack. for the 03 its nice having the adjustability of the powerpuck in the cab. just thought some would find it helpful. i am having a issue if my coolant temp running 210 while pulling i think i am having issues with the overflow. the truck has 95k miles and probably 3700hrs. i guess its time to change out the overflow. everyonce in a while the coolant temps would drop back to 180 for about 10 minutes then right back to 210 is doesnt matter what the temp outside is. i think i remeber eb having this problem. oh yea at part throttle while coasting down a hill i get the slightess miss. any suggestions?

I love my Pred 100 hp for towing - plenty of power for my CGVW and great driving manners and low egt. I REALLY like Extreme - egt is low enough but I can't stand the touchy throttle for very long. I've thought about stacking an EZ for a little pressure cuz nobody seems to be very impressed with the Diablo stack. I thought the Puck 90 was a bit too much pressure? Craig