I am in SC. Own a 1970 f250 2wd camper special. I want to make it 4x4. I have searched and searched and the answer that always comes up is to swap frames to a 73-79 frame for various reasons including better steering, brakes stronger frames etc etc.

Problem one:
The cab is more or less a direct bolt up, BUT....the bed is 3+ inches behind the cab because of the different frame length which won't work for me.

Problem two:
You may have to re drill your bed holes to fit the wider rear frame rails, which is not a big deal.

Problem three:
My frame is gorgeous, and finding a quality non-rusted non modified frame in the vicinity of SC which has been tough because of the HIGHLY variable definition of RUSTED....

Leads me to my question (finally).... I have been looking at my 70 2wd frame, and looking at the 78-79 4wd frame (in junkyards) for literally months. I have made measurements and taken pics to compare at home. It looks like the ONLY difference in the actual frames themselves is the riveted in crossmember/engine mount in the 2wd, and the welded in 4wd cross member/boxed frame assembly. The shape and size of the frame rails seem identical.

What would stop us from torching out the 2wd crossmember, cutting out a donor 4wd crossmember/frame boxing, and transferring the 4wd crossmember/frame boxing to the 2wd frame. Then you could use OEM 78-79 steering (ideal), front leaf spring mounts and springs and the oem shackle hanger?

What am I missing here?

 

Hi,
Read your thread.....When you start figuring all the fabrication needed to "cut "out the old cross member and patch in a new one,fab in motor mounts,fab up a new steering box,fab in suspension points (aka radius arm mounts & such) fab up a transfer case support (not to mention is it a divorced or married)and have custom sized drivelines made, you can see where it would be much easier to use the later 70s frame,relocate the bed and drill new holes,or shorten the frame 3 inches,and bolt everything on. (a lot of people think cutting a frame is taboo, but we do it all the time at our shop, and the heavy truck industry has been shortening frames for eons.)
You didnt mention if you plan on lifting this truck or not, actually if its lifted 6 inches or better you dont have to worry about the 2x cross member....

Matt

 

don't swap frames. leaf spring front suspension for a 4x4 swap isn't that hard to understand and figure out how to make it work for your truck. you can do it with mostly junkyard parts or cheap factory replacement parts. i suggest you post this question in the 4x4 forum, and you will find some very helpful answers from some very knowledgeable members

 

Thanks for your replies. I actually posted it here instead of the 4x4 forum specifically because I was really only looking to see if there was any differences between the shape of the outside frame rails on a 2wd to 4wd, 70 vs 78-79. It looks vitrually the same.

IF there is no differences in the shape of the front half of the frame (big IF but maybe), cutting out just that portion and grafting it in should be simple and would allow the use of all OEM parts as a bolt on affair. OEM motor mounts, OEM front leaf spring perches and shackles and springs, OEM (78-79) steering box and steering components (except maybe a dropped pitman arm). As far as the trans/transfercase those are bolt on crossmembers anyway and should just transfer over ***** nilly.

In my mind I could either fab all this up on a 2wd frame (which some one else in this forum did and said he would never attempt to do it again because he had to do 6 inches of lift to clear the 2wd crossmember and steering was a nightmare because the 2wd box is backwards) and hope it all works in the end, or just transfer a sub frame assembly that Ford engineered from one frame to another and use all oem parts as a bolt on project. I prefer the simpler of the two IF it is at all possible. If not I will continue to hunt for a rust free frame local to SC.

 

Oh, about lift; I would be willing to go up to 4". What ever is needed to clear 35's. I'm not that far ahead yet. I'd like to start at stock height if at all possible and go from there.