Purchased a 1986 F150 2wd today auto today with the 5.8 4v HO.

I have a 1981 F150 4x4 auto with a 351M.

My plan is to swap the 4X4 components and swap the 351M/C6 from the 81 to the 86.

The 1986 has 48000 original miles one owner, but the previous owner ran the engine without coolant and for sure blew a head gasket (not sure what else) not a fan of the W engine anyways. The 86 is cherry, still has the factory jack and tire iron under the hood. I know a lot of people would gut the emissions but I am trying to keep this truck as original "looking" as possible, minus the 351m and 4x4 swap.

My question is, will all the A/C, smog, alternator, etc bolt up to the 351m from the 351w and also what is involved in swapping the 4x4 components.

Note the 81 had the entire front end rebuilt before it was literally parked and the reason for the swap is the 81 is rusted past the point of reasonably fixing.

I do all my own mechanic work and have restored multiple CJ7's, I am 100% positive I can do the swap I am just wanting to know more specifics from the gurus, i.e will everything bolt over after removing the pesky u-bolts.

I have been reading the forums for the past couple days and here is a list of what I have noted:
Parts from 81:
-Springs perches
-Radius arms and brackets
-351m/C6/transfer case
-Drive-lines
-Front and rear axles
-Transmission cover
-4x4 wiring harness
-Rear leaf springs and blocks
-All of the TTB (spindles, hubs, etc)

Josh

 

To be honest I wouldn't replace a Windsor motor with an M motor purely because of the aftermarket support. Not that the M has no support, but it will cost more mod for mod. Also, the W might be more responsive to cheap mods (carb, intake, heads/head work, exhaust) than the M. The 351 HO also has the better 4v heads and 4 barrel intake from the factory. I would find a new W block and transfer the HO equipment to it imo

 

It will be trial and error on what will swap on the engines. These engines are not related at all, so I will say probably none of the brackets will fit. You may be able to mix and match some things that will work. If the 351m wasn't a A/C engine, it may be a challenge getting the correct pulley setup for it.

You don't have to change the rear springs and hangers if you don't want to. I know the facotry put 3 inch wide springs on the 4x4 models, but people run the 2.5 inch springs with 4x4 swaps with no problems. You could split this project up if you wanted to get it on the road. Swap the engine and tranny. Drive it. Then swap the rearend, drive it. Then swap the frontend. Your done.

With the ttb, the whole assembly bolts in place, so you don't have to worry about the spindles, brakes, etc. You may have a little problem when you get parts. When you go to get brake parts you might have to tell them you have a 86. They did change a few things through the years that might make some things different.

 

Thank you for the responses, always love this forum because most everyone is nice. Thank you for your input DeereFord300, this is just not practical in my situation due to having to buy a new w block and a small block 4wd C6



Will the internals from the Small Block C6 interchange with the internals from the Big Block C6.

This might be a silly question but will the exhaust manifolds from the 351w work on the 351m, I think I remember reading that the heads will swap between the two but some water jackets are missing and that is why they are incompatible.

 

No, the exhaust manifolds won't swap. And the heads won't really swap without work. As was said, those engines are entirely different.

If rust on the '81 is the problem, why not swap the 86's body onto the '81? It will be a whole lot less work. Pull the fenders, disconnect the wiring harness from the engine, pull the 4 bolts where the cab bolts to the frame, and remove the cab. The bed is even easier.

 

Whoa, Gary, you're forgetting about the steering column.... not that that adds so much work, but it's still not as easy as you're making it sound.

 

I thought about that later. But, you should be able to leave the steering column in and just disconnect it from the sector box.

And, there's the A/C system if he has one. You could leave the system intact on the 86, but it uses a different compressor than the 81, and the mounts are different.

So, you are right - it isn't as easy as I made it seem. But it would still be far easier IMHO than the other way 'round.

 

The above is one of those mix and match things and you might make it work. The old york would probably work ok wouldn't it?

You can check the stickers on both trucks, but I doubt it will be much difference. The 4x4 will be a heavier truck, so don't let that fool you if the gross numbers are higher on it. The 2x4 guys haul just as much as the 4x4 guys with no problems.


The 2x4 swap to 4x4 is a true bolt in on the f150's..

 

I thought about this but the frame is rusted through in the 81 in a few places.

 

Awesome thank you for all the info guys, and when I figure it out I'll let you know how I did the brackets for the engine accessories.

 

Or you could put a new engine in the 86, swap the 4x4 stuff to the 86, put the whatever the 86 had in the 81 and sell the 81. That would be the easiest thing to do.