Picking up my first Dodge on Tuesday (coming over from a Ford PSD) Anyone know the ratios in the 6 speed tranny? How much abuse can this tranny take (I know the stock clutch will be the weak link at first). But I plan on modding the truck, but am wondering about the stock tranny on how much abuse it can take. What about the rear end on the dually? What size ring gear does it use? Looking at adding exhaust, air intake, and a programmer (undecided at this time on who to use). I want to put in the neighborhood of 650-700 Lbs ft of Torque and 325-350 HP to the tires. The truck I am picking up is an 03 QC LB DRW 6 speed HO.
My dad has an '02 H.O. 6 spd. There is basically no weak point in the manual H.O. drivetrain besides the clutch. The NV5600 tranny is bulletproof, you'll never have a problem with it regardless of power and load. The rear end is an AAM 11.5" rear, it's huge, no problems there either. The clutch is going to be your main problem. My dad's H.O. is probably putting out nearly 700ft lbs of torque and his clutch doesn't slip when accelerating. He has only had his new found power for about 5 days now and hasn't pulled a trailer yet with it so I can't say if it's going to slip loaded or not. From what I have heard, it shouldn't. Your '03 should have the same clutch setup IIRC. You should be ok with the stock clutch at 700ft lbs and down, the rest of the drivetrain should be able to take nearly double that without much problem.
