I would be fine with a 4X4 conversion if the cost were reasonable and the results reliable. That said, I am not very experienced with 4 wheel drive and from my google level research it looks like $5K plus and a cob job. If it were $2-3K and the result reliable it would be a easy decision. Is this a realistic cost? I am comfortable doing the work and hunting parts. Thanks, Rick
Google search is really only useful to for narrowing down better sources for the information you need - in this case those would be
Powerstroke Army and
Powerstroke Nation. I'm not saying you can't get good advice here, but statistically you have better chances over there as all they drive is Fords, whereas here we have a huge mix and match of everything. You can also try ih8mud and of course Pirate4x4. We have seen in person an OBS ('96 IIRC) converted to 4x4 using the '05-up coil-spring axle, I can assure it was anything but a cob job - from what the person was describing it was nearly a bolt-on affair, and information on the aforementioned discussion boards seems to confirm that. IIRC the only thing he fabricated was a tracbar mount as the Superduty one wouldn't work for his frame, but you are starting off with a Superduty truck so rhis may not be an issue for you.
Where you can screw up hard is while fabricating the crossmember to support the transfer case if you go with a standalone NP205 as I had suggested earlier. However now I seem to recall seeing it mentioned somewhere that the 4R100 transmissions are able to be switched between 2wd and 4x4 by simply swapping the tail housing and output shaft while transmission is still in the truck - that would allow you to run a standard "married"-type transfer case (bolts up to the transmission directly) so no fab work then, heck if you're lucky you'll even be able to use factory driveshafts for a 4x4 truck of your model. That is if your truck is automatic, with the stick-shifts IIRC the trans has to come apart, which oddly enough is what we'll be doing soon to get the gear ratios we want in the case we need.
As far as cost goes, that really depends on where you source you parts and what condition they're in. We've bought cheap axles that needed very little amount of work to bring them back to 100%, and we've seen some listed for a grand nevermind they needed at least half that in additional parts to make them semi-reliable. Shop around, don't be in a hurry, check regularly your craigslist for someone parting a wrecked truck and the junkyards for one that was already scrapped. $3 budget should be easy to meet as long as you don't have to regear the axles, pretty much everything but a gear swap is very DYI-friendly so you'll probably only be paying for the parts.
Having said all that, I think you should first upgrade your current equipment as suggested by the other folks here. If that's not enough to get you in (and more importantly, OUT of) the places you wanna visit then start gathering parts for the 4x4 swap. Tho IMHO everyone who has the opportunity for an easy and affordable 4x4 swap should jump on it, true it may not be needed 95% of the time but the other 5% can save you big on tow-truck services and possible repair work

We do not own anything that isn't 4x4, if it was 2wd when it left the assembly line it gets switched to 4x4 first chance we get - it's better to have it and not need it than to need it and not have it
