I'm picking up a '79 F-250 (351M, single cab, long bed, 4wd, 4spd) from my dad this summer, and I'm putting together my "shopping list", if you will, of repairs and upgrades I'm going to apply to it once the title is transferred. Its current status is, well, pitiful. The cab corners are history as are significant portions of the doors and fenders, and the bed rotted off long ago. The motor overheats roughly every 20-30 minutes, possibly because the fan shroud doesn't match the fan size. The transfer case and both diffs leak, 4-low is a pipe dream...

I already know that I'm going to swap out the crank and pistons to convert it to a 400, and will almost certainly get upgraded heads/cams/intake/carb/exhaust to boost power and efficiency. No idea which axles it specifically has already, but if it doesn't have the 3.54s, you can bet I'll be tracking some down for it.

The only major question at this point is the body options. I'd ideally like to try to put an extended or crew cab body on it so that I can justify the expenses to my wife a little better ("Look, honey, it's a family truck now!"), but I don't know if there are limitations on doing that on a single-cab frame or not. Like I said, there is no bed to speak of right now--it's currently carrying a farm spray tank/boom assembly--and I'm not opposed to using a flatbed instead of a traditional pickup box if I have to. Has anybody ever done this kind of a swap before, though?

Give me some tips/tricks/pics if you have.

 

I've got an extended cab on a regular cab long bed frame. I didn't do the cab swap but from looking at what has been done the last body mounts on the cab don’t line up to anything so custom mounts will need to be used and the body required a 2" body lift to make everything fit.

Mind didn't come with any bed so I made a short short bed for it that was about 6" shorter than a short bed but I did it by taking 30ish inches out of a long bed.

The swap isn't all that hard and if you are going to build a flat bed it would be easier than sectioning a normal bed.

Sorry no pics because it's all apart for a full air ride suspension and front and rear 4 link conversion.

 

you can use the stock cab stands off the supercab (they are diff thant he reg cab) and a body lift to clear the frame hump. obviously you will have to cut down the bed. For a crew cab, the same procedure, only the rear of the crew cab will be extremely close to the rear tire. more extensive body mods would be required if you want to keep a stock type bed. There are have been a few threads where people posted pictures of them.

 

here is one https://www.ford-trucks.com/forums/1...cab-frame.html

 

I like the idea. So much so that I plan on doing it myself! Although my plan is to put the supercab, or possibly a crew cab on a 80's-90's F-250 4wd so I can get the d50 TTB.

Anyway, as others have said - it can be done, it just takes a bit of fabrication. Personally I plan on cutting into the body if the bump in the frame is a major issue as I'd rather do that than run a body lift, but that is just my & I'm by no means "normal"

 

Thanks for the tips. I had poked around but didn't find that example; thanks for that. I personally don't want to get too much into metal fab if I don't have to, so I'll probably stick with a flatbed for the time being. That black rig from the linked thread looks pretty cool, though, so I won't rule out getting a shorty bed for it in the future.

Once the truck is in my hands--probably in June--I'll post some pics of the before/in progress/after stages.

One other question...the frame on the truck is amazingly quite solid, with only a little superficial rust or rust stains on it. I will be cleaning it up and repainting it before I put a new cab on it. Based on what I've seen on here, it looks like the options for cleaning it up are sandblasting or perhaps using a phosphoric acid wash. Are there any other options, perhaps that might not paying someone else to do it or dealing with caustic chemicals? (Never used or heard of phosphoric acid before, so I don't know what's involved with that. Can I just pour it on the frame and rinse my driveway clean afterward? Feeling doubtful about that, but who knows...)

 

Rent a steam pressure washer if you just need to clean it up and take off the crud.

If you don't want to do a body lift on stock cab stands you can also raise the body mounts, though the stock stands are not conducive to raising so you would have to make something. relatively simple, really. The stock ones are a complex folded heavy gauge steel, but it just needs to be a right angle bracket of sufficient strength. If you want to avoid heavy fabrication your best bet is the stock ones plus the body lift.