I tow a 38ft 5er that weighs about 11,500 empty. I am pulling with 99 3500 with nv4500. Only mods on the truck are power puck and sb intake. Have a 4in turbo back on the way and gauges w/pod to install. Truck has about 145K miles. Now to the question.

How will the stock transmission hold up to pulling this rig? Suggestions on clutches and tranny.

 

My truck is exactly the same as your in stock configuration except the dual rear wheels and I pull 30,000 off and on through hay season no problem. The tranny is no problem at all as long as you don't go crazy on the added HP and don't lug 5th gear. It can be built much stronger when the time comes for a rebuild. You can check my signature for truck details but this thing is a pullin machine wen it comes to trailers.

I turn the Comp off when I'm towin heavy cause it raises the EGT's way to fast and the mighty Cummins don't need it anyway for towing, it's just a toy for playin.

First thing you need to address is a new fuel supply, as in lift pump to supply enough fuel to keep the VP44 healthy and gauges. A fuel pressure gauge mounted where you can see it at all times while your drivin and an EGT/Pyro gauge. Your playin the odds right now with that $1200 injector pump if you don't have these things.

 

I have a fuel light now, fuel gauge, pyro and boost are in the box waiting to be installed when i get home.

Trying to decide between the fass and airdog. what is a raptor
Don't plan to mod anymore, just need a tow machine.