Thinking about getting another Dodge Diesel for towing and have found a great looking 97 12 valve Duelly long bed.  Only 166,000 miles on it.   I want to go through it, pull the bed off and build a flatbed for it to haul my quads and possibly tow my travel trailer.  I currently have a 2000 5 speed that is great but thinking of adding another one to my stable.

  I’m just wondering what the weak link, Achilles heal is on them, like the lift pump is on the 98.5 to 02 models.  How are they to build for torque and power for towing?

Speaking strickly from what I've read, the main things needing to be address are the KDP and the 5th gear nut if applicable. Other then that just general wear and tear item that would need replacing on a 20+ year old truck. 

 

Tuning from what I understand is as simple as turning a screw one way or another, there's a meme that covers this but I can't find it. Easy enough to mess with tuning is what I'm getting at. Hopefully someone with actual 12v experience can chime in and help you out a bit more.  

I found the lift pumps, even the ones from Cummins to be inferior quality from what the original was on these 12 valves. I kept finding the linkage broken inside after about 100 -120 k miles. The original lift pump from 1992 is still good and built with better hardware. I finally had to put a fuel pressure gauge on the old girl to watch 6 p.s.i. needed for the VE. I've since sold this truck though and love the second gens.

Lot of guys even on the 12V's gave up on the factory lift pump and switch to electric pumps like AirDog / FASS because of the limitations of the mechanical lift pump. The Factory lift pump doesn't pump when the cam pushes the rod. It pumps when the cam lobe rolls away and when the rod is returning under spring tension. So this makes the lift pump volume lower at high RPM's. There is a article on Tork Teknologies site about the flow limitations.

 

For daily driving, the factory lift pump will work...

 

 

  Seems like Dodge didn’t learn anything with the inferior lift pumps when they went to the VP44.  Seems once you get rid of that factory lift pump that it takes care of several potential problems.  I changed out the one on my 24 valve about 6 years ago and don’t regret it.  

  Problem I just found out from my son is that in California once you put a flat bed on a truck it increases your registration fees and your required to stop at truck scales.  Government gets you coming and going.

1. I ran a torktek pressure regulator for a couple years, I found that it bled off too much volume and I was loosing top end fuel pressure because of it.  I located a stock one and did the  "bic-pen-mod" to up the pressure.  It runs way better.  It pulls hard all the way through to the governor now.  I run a modified factory lift pump on mine.  It is modified similar to what PDD sells as their  hotrod  lift pump.  

In response to the original poster, the 12 valves don't really have any problems.  Killer Dowell Pin is about it.

 

More power is pretty dang easy as was already stated.  You can double the power for now much of an investment.