Hello fellow Ford truck fanatics!
I've got a couple questions about converting a truck to 4wd.
I have a 1980 F150 2wd, and can get my hands on an 85 F150 4wd. The 85 body is mostly junk, and the engine is gone. Otherwise, it's got the complete drivetrain including 4sp and transfer case.
Would the IFS from the 85 4x4 bolt onto the 2wd frame? If so, are there any of the brackets/mounts that must be swapped, or are they the same?
I know the trans/transfer case and rear axle will swap with minimal issues.

Both trucks are reg cab LWB, so I know this can be done, even if I have to swap my body onto the 85 frame, but I'm not 100% sure about the 85 frame being straight or rust-free, like my 80 frame. Plus, there could be problems later from the frame numbers not matching.

The funny thing is, I pulled the engine out of the 85 10-12 years back (belongs to my former bro-in-law) due to needing replaced/rebuilt. He had another 300 I6 in a wrecked truck, but never did anything with it.
The body was a little rough and had minor rust when it was parked, but the years and weather have taken their toll on it, since windows weren't shut, and some are now missing.

I know this sounds like a lot of effort, but I've had my 80 for a long time, and the only thing I have wished it had, was 4wd. Aside from minor rear fender lip rust, the body is great. Heck, the whole truck is great, other than needing a little extra help dealing with snowy, hilly roads.
I might miss the C6 auto by going 4wd, since that truck had the 4sp, but that's not an issue.

Thanks!

 

The 4wd stuff will bolt right in, no trouble at all. Your only aggravation will be swapping the pedal assembly out and installing the hydraulic clutch master cylinder. There is a late model clutch pedal assembly and a early model clutch pedal assembly, but I think the transition year may be around 87, but I am not sure. Will the hydraulic pedal assembly bolt right in your truck, which would have originally had a linkage system if it was a manual? I am not sure of that either, someone probably knows about this though.

Some people do this swap in stages. They will take the 2wd frontend out and install the 4wd axle, and drive it around like that till they get a chance to swap the tranny/transfer case in.

 

Excellent news! Thanks so much. I figure the pedals should swap rather easily, since the cabs are practically identical. If not, I have great fab skills.
Honestly, I'm not a huge fan of the 8.8, due to the axles/bearings, but I know it would be nearly impossible to find matching gear ratios for the IFS and 9" rear. Oh well, it should drive and pull at least as well with the t18 and 3.08 gears as it does now with the C6 and 2.75. I plan to run the 31-10.50-15's all the way around, rather than just on the rear like I do now.

Now all I gotta do is convince him to let me have that 85 chassis for nothing or next to it. He'll never do anything with it, except maybe (big maybe at that) send it to the scrap heap......

 

The pedals with bolt right in, I have an 81 cab on my diesel. However, the firewall reinforcement plate at the booster isn't punched for the clutch master like the 82+ trucks, so, you have to do some careful measuring. What I did was remove the plate from the firewall of the old cab bolted it on to the boles for the brake master, and used it as a guide for drilling the new one..
The front end swap couldn't be easier, I have done it on a few trucks now, if all the bushings etc are in good shape on the 4x4 front end, you can have the swap done inside of 2 hours. You just unbolt the radius arms, the pivot bolts, the shocks, and the springs, tie the calipers up out of the way and drop the 2wd front end out, and do the opposite to put the 4wd one in.
For the transmission/t-case, you will need to swap the cross-member and all out of the 4wd, but it's no biggie, still a bolt in.
About the only minor pain about your swap is that your truck has a solid floor pan, but, it is stamped where the bolt in panel goes in a manual truck. What I do is lay the tunnel cover from the donor truck on top of the floor, mark out the holes, and then cut about 3/4" inside of them, which is about what the factory did. I usually use self tapping screws to retain it rather than the factory clip and bolt setup.
This is the 81 F100 that donated it's cab to my diesel:

It's one of the trucks I have converted.

 

Man, you guys are making my day. I've been doing some research, and it appears that all the braking components are the same, aside from the front rotors and rear chassis to axle brake hose. Considering I've replaced everything except the hoses, that's good news.
It even appears the new front springs under the 2wd are also the same as 4wd.

The floor pan part I was aware of. I haven't yet decided whether to use self tapping bolts, or go borrow my buddies "Rev-nut" tool that installs a threaded sleeve, and locks it in place like a pop-rivet.

On another note, it appears like I need to add another line to my sig. Picking up a 95 Mazda B2300 (Ford Ranger) for $700. I expect it to be my son's daily driver as soon as it gets the once over.

 

Riv nuts are a VERY nice solution if you have access to them.

 

One more "silly" question. Is the steering linkage different? I know my current tie rods/ends are in fantastic shape, but I have doubts about the ends on the 4wd since it has been dormant for over 10 years.
If the tie rods can be left alone, I'm in good shape. If they have to be 4wd parts, I may have to drop a good sized chunk of change on new ends.
I plan to inspect and repack/replace any parts that need attention, and I remember the tie rods/ends can get rather pricey from my parts counter days.....
Ball joints, wheel bearings and u-joints are pretty much a given for needing a close inspection, with a repack or replace as needed. So is a total fluids (trans/transfer/diffs, brake/clutch) change.
Hopefully, my current starter will hold out long enough to facilitate rebuilding and swapping the nose at one time, rather than a return trip to the rebuilder. It's acting up occasionally, so a rebuild is due soon.
I'm planning to keep the ol' truck around for many years to come, whether I can get the 4wd swap parts or not. I've had a 3.25 ratio pumpkin for a while, but never got around to swapping it for the stock 2.75 gears. Looks like it may get put off permanently.......

 

The tie rods will bolt right up., no issues there.

 

Man, you never quit with the good news! Thanks very much.

I'm sure that I could have figured all this out thru trial and error, but it's great to have this level of info at your fingertips.

 

I have done this swap and the real bad part is the rear leaf springs are wider on a 4x4 than on a 2wd so if you choose you will have to swap them out. This is where the work comes in, those rivits are murder. Other than that just alot of wrench turning and time. good luck

 

Rivits are easy. Torch or grinder to remove the head, and a hammer/punch to pop the rest out. Air chisle works good too, as long as you don't waller out the hole........

 

I did the 4wd conversion on my 96 F150 last spring. Everything bolts right in with ZERO drilling, cutting or welding. You may have to cut out the trans tunnel on your 80 because it was an automatic 2wd, that's easy Ford dimpled the area that needs to be cut out. I had to drill 3 holes on my truck only because I installed a 2.5" suspension lift (had it laying around from another project) along with the conversion. As previously stated the 2wd rear springs are narrower (2.5" wide) than the 4wd springs (3" wide), I am still running the 2wd springs with no issues, I added the factory block that stock 4x4s run. Everything up front is all pretty much interchangeable: Coil spring buckets, coil springs, TTB/TIB brackets, radius arm brackets, steering linkage... you more than likely need longer front shocks. Pedal assemblies will interchange, I would suggest going with the newer hydraulic clutch set up... it seems to work better. The 4x4 trans crossmember bolts right in the same place as the 4x2.

 

I have done a lot of rivet removing. The easiest and fastest way I have found is to center punch the head of the rivet, and then drill the head till you get near the frame. Pick a drill that's close to the size of the rivet shank. Once you eat most of that metal away with the drill bit, a chisel and a hammer will cut the head right off in one or two blows. Then the rivet shank will punch right out.

 

Yeah, I've used that method too. It came in real handy replacing upper ball joints on the ex's 70 maverick about 20 tears ago.

 

Cool, I didn't find this before now, but there is even a tech article on this site covering the conversion.

2x4 to 4x4 for '80 to '96 F-100/150's .: Articles