I have a 1994 F350 7.3 IDI CC dually 2x4. This is a Centurion Pacific. First I want to say do not tell me to buy a 4x4 like my truck as there are not many trucks like mine in 4x4 with less then 120,000 miles. I have the capability to add the equipment and the mechanical aptitude. I do not drive my truck a lot, hence the low miles but when I do it usually to pull something or it has snowed. There have been times I need to go of road. I have to be careful as everyone who has a diesel knows the front of these trucks are very nose heavy. If I have no weight in the bed my truck will nose dive into any soft material. This is why I want to add 4x4. It should help pull the front through. Since I don't drive it much and I need to keep the ride height close to stock, I would like to use a Dana 50 IFS. If I use a Dana 60 the front will rise substantially. My question is what year models front axles would be the best or closest bolt in? I was told any F250/350 4x4 above 2005? I'm sure there will be some fabrication involved and I am expecting this. I am not afraid of this as I have rebuilt my E4OD by myself after 1 yr of research and I also had to build myself a special tool to set the clutch assemblies into the case. I couldn't afford the real tool so I made mine own.