how hard well it be to do a 4x4 swap, i want to take the 4x4 stuff from my 78 f150 shortbed and put it on my 4x2 74 f100

 

the f100 is a long bed

 

Unless you have welding experience, a decent place to work, etc It's a lot easier to swap the body from the 4x2 to the 4x4 or find a 4x4 frame and swap. With the price of parts trucks getting cheaper I can't see the hassle of a 4x2 to 4x4 suspension/axle swap

 

You could always try to sell or trade your short bed for a long bed 4x4 to do the change over. It's much easier to do a body swap than the drive train swap. There are many trucks out there and if you don't need a good body than there are even more. It's better to start with a 4x4 long bed truck. But, that's just my opinion also. If you are a fabricator and welder than go for it.

 

I am not entirely convinced there would be a great deal of fabrication involved. They are both coil sprung vehicles. That is if I remeber the 4x2 F-100 from 74. The coil buckets would stay the same, and the axle from the 78 would just roll right under and bolt up using the 78 coils. The radius arm brackets would have to be removed from the 78 and installed under the 74 frame, as would the trac bar bracket.
The most difficult part will be installing the transfer case to the existing trans, or you just might decide to use the other trans. No mention of engine or trans combos. At least one driveline will have to be made or at least shortened for the rear,but again depending on the trans combo, the front might just fit right in. The crossmember or frame will have to be modified, but this will be dependant upon which trans you use.
All in all, when someone asks about a 4x4 conversion, we usually suggest that someone find a donor vehicle to make sure they have all of the required parts. You have everything that you need, and should require little welding, if any at all. The fabrication skills are really not too important since the components are almost the same. You are not re-inventing the wheel, just bolting it up to something else.
While the body swap would be easier, except for the frame demension issues, the 4wd swap should not be as difficult to tackle as most would think, or make it out to be.
Think the biggest issue would be steering, but even that is easily overcome. No, come to think about it, even the steering is terribly easy.

 

I'm pretty sure if you look into it closer there IS a great deal of fabrication involved. IIRC, the 2wd cross member is different than the 4x4 cross member and has to be changed. This requres welding as well as a lot of careful measurements and fabrication to ensure the crossmember goes in square and is aligned properly. Also the frame rails must remain properly aligned.

Believe me, it's not a simple bold on. If it were, enough people have looked into it, a simple method would have been found to do this swap.

 

[QUOTE=76supercab2] Also the frame rails must remain properly aligned.

The frames never come apart, so the relationship between the two sides will never be compromised. The crossmber for the donor truck could be used, after all, it already fits the transmission / transfer case combo.
Getting rid of the 2wd front suspension is pretty easy, although I would expect that you would have to run some type of lift to clear the front diff from the existing crossmember and pan, but that isn't too tough either. I do not have a 2wd in front of me right now, but the 74 that I have now was a 2wd, and it was not all that tough. The crossmember came out of a 4x4, and bolted right in.
For that matter, you could find a NP 205 divorced case from an pre 77 ford 4x4, and keep the 2wd transmission. With the right placement of the case, you could really make it so the same lenght driveshafts could be used from front to rear. This would minimize the amount of spare parts you need to carry off-road. This divorced set up could be a salvage yard find, and the crossmember would bolt right in, provided you removed the crossmember hangers / brackest from the donor vehicle.
As long as you could read a tape measure, it should not be that involved. I don't see yet where the "Lincoln glue gun" even needs to be plugged in.

 

It shouldnt be really that hard. If i remeber correctly the frame rails themselves are the same. The only difference is the front crossmember. To deal with that issue as 75f350 said a 6 in lift should clear. You can also modify the 2wd crossmember. You only need to shave a few inches off of it.As far as the transfer case crossmember goes If you use the tranny and transfer out of the 4wd just bolt it in then slide in the crossmember and bolt it where it needs to be. Then you radius arm brackets bolt to that. The only thing that i think you would have to do is reinforce the drivers side front frame rail infront of the motor where the 4wd steering box bolts.You can shorten your 2wd rear driveshaft and add the 4wd slip yoke. I had to do that on my truck when i changed from a auto to a 4spd. Your local drive shaft place should be able to do that for you. As far as the front shaft it should bolt right up. THis is assuming you are using the tranny and transfer out of your 4wd. Thats all i can think of for now ill reply later if i think of anythin else.

 

the 4x4 drive truck has lift i do believe, its sitting on 38 inch tires with rancho springs and stuff

 

and yes im going to pull the engine out of my 4x4 its a 390 and put it in the 2wd which has a 302 in it