Good questions. I guess the best place to start would be pricing all of the necessary components to convert it. Depending on what you can find in salvage yards, etc., it may be do-able. I've never tried it myself. I just ordered mine as 4WD when I bought it. Having said that though, as far as I know, all 1999 to 2004 F-250 / 350s were leaf sprung in the front end. The coils and radius arms started with the 2005+ models. There are a lot of these trucks and parts in the junkyards around here so I don't think finding the parts will be the problem. The biggest cost is probably going to come in the form of the labor involved. It depends on how much of the work you can do yourself.

To be honest, and others can chime in, you would probably be just as well off to buy a good used 4WD or trade yours for a new one. With the current offers from Ford, you can actually get a pretty good deal. I know what you're saying about the cost and mortgage, etc. It's a big pill to swallow. If you convert yours, you may spend a lot of time afterwards trouble-shooting problems as they creep up.

I'm guessing that you'd be better off to find a complete undamaged 4WD chassis and just swap your body, etc. on to it. By the time you get all of the necessary components (front axle, transfer case, rear spacer blocks, springs, steering gear, etc.) and then pay someone to install it and convert yours, you'll probably come out better financially.

Just my $.02 worth. Also, if you decide to convert your current truck, take some good photos along the way to post here for others considering the same.

Good luck with whatever you decide!