marmon-herrington, in Louisville ky, converted f 450s to 4x4 in the years ford didn t make 4x4 f450. very expensive front axle parts ie: 400.00 tie rods. I put almost 300,000 miles on an f450 4x4 conversion , pretty much trouble free, but I wasn t buying parts company I worked for was. I would stay away from a converted f-450 unless I was going to replace axles with newer superduty or f-350 parts. Parts were hard to get 20+ years ago. We never broke a spring or frame that I knew about , and we had 10-12 at all times . Truck I had had a 5.13 gear in a dana 80. Used the closed knuckle front axle, ie like old jeeps, seals leaked a lot on these. Trucks would haul anything you could put in them, I used to haul a bed full of firewood in if I had to cut tree off line. Trucks weighed around 14,000 loaded. We had 1 gas with a 460 , you would have had to have an oil well to run it, if you owned it. Mine was a 96 model. When that 1 was completely worn out got a 99 model, definitely a downgrade from an obs body in my opinion. The 96 was the first Powerstroke I had any dealings with.