This is an interesting discussion of the age old question? "do I restore it or Mod it?"
There are many FC's still around. They enjoy a limited following mainly due to the fact that they are just Butt Ugly!! As we all know "Ugly" can be cool.
The short WB single cab versions are the most plentyful. The really cool ,and also most rare ones are the Crewcab long WB models which were used mainly by the Air Force as Crew and flight line vehicles.
None of them are in anyway to be considered good offroad vehicles, and there is very little you could do to one to make it into a decent wheeler. I guess you could unscrew the steering wheel and drive a TJ under it.
However they can be built in to very useful towrigs or light offroad (dirt road) type or bad weather terrain vehicles. One could be set up as a Expedition type vehicle with an Alaskan camper, which I think would be cool for a trip into Canada or the far north. Or as a hunting vehicle.
There is a website:
www.thefcconnection.com which has pictures of about 500 different vehicles. My personal favorite is the Black Crewcab with the dual wheels on the back. The guy that ownes it Jesse Ybarra(Phoenix AZ) has been looking at replacing the 350 Chev motor with a 4BT. He uses it mainly as a tow vehicle. It is a very cool vehicle!
Fred Williams, the tech guy for Petersons 4wd mag has a crewcab version also, and is looking at putting either a 4 or 6BT in it. It is in the December issue of Petersons 4wd mag. Fred is a first rate fabricator and in addition has access to many services and sources for parts that most do not. So this job would be much easier for someone who has the full resources of a magazine group to tap, rather than regular you and me who have to fight for every part.
Any way you look at it you are looking at a 100% redo which will take you 2-5 years to complete, and cost a significant amount of money. I see $30K easy. You better like what you end up with and use the hell out of it, because you will be married to it. There is a very narrow market for this type of vehicle and I can safely say there is almost no possibility you will not get out of it anything close to what you put into it.
My personal opinion on the decision to restore or hotrod lies in the overall condition of the vehicle you are starting with. If it is nice to begin with then restore it. Because you can then sell it. If it is like the one in the pics (and most are) above with the MBZ motor then I see no reason to not modify it so you can use it for something other than a vehicle to attend FC rallies with. If you change it to make it more useful and you finish the project and it does what you want, then I say, knock yourself out.
If you just destroy it, then you suck, and need to be kicked! Like they say they ain't makin' them anymore, and if you can''t make it better, then sell it to someone who can and do something else.
A 4BT or a 6BT will fit but you will have to heavily modify the frame, and the floor of the cab will also have to be modified considerably, the entire drivetrain will have to be changed, look at some build ups here at the site to see what types of drivetrains you can assemble. I would not do a short WB FC150 at all. They are basically a CJ5, and are not going to be good for anything in the way of towing, but they are cute. The FC170's are basically CJ6's and are better, but the best and most useful is the Crewcab as it has the longest wheelbase. You can put 4-5 people in it and still have a 6ft bed to load up.
It is a doable project, but it will not be an easy project.
You need to really asses your finances and skill level before you jump off this cliff.
Here's some pics to show you what is possible. The first 2 are the same truck,and now it has polished aluminum dually wheels on it. The 6 wheel one is a diamond in the rough, and they also made a van/camper version. I bet the green one's name is "Kermit". You can spend an entire afternoon on this website there is alot to look at.
Randy