so theres a crew cab for a decent price near me but it's 2wd and has a service box what kind of can of worms would i be opening up to do a 4x4 conversion and is the frame behind the cab the same as all the other 2wd trucks (it would save me some sheet metal welding)? also what front axle would i have to source? any thoughts or info are appreciated.

 

from what i have gathered it is a P.I.T.A.
first off the beds are the same for 73-76 and 77-79 are the same, the 77-79 will fit the 73-76 trucks the only difference being it has a fuel flap instead of a fuel cap- the 73-77 highboy beds have a narrower bolt pattern if i recall correctly and some dont have a hole for a gas tank all together.
on the axle i guess that would depend on whether or not you wanted a 1/2 ton or a 3/4 ton, if 3/4 ton i would look for a dana 60 front and a dana 60 rear, 1/2 ton i would do a dana 44 front and a ford 9".
i think the frame has to have some clearance done to accept the 4x4 axles and you may have to fabricate some of the 4x4 mounts
all this been said i think if you want to turn it into a 4x4 you would be better off buying a 4x4 crew cab frame or a crew cab truck thats already a 4x4, as this will take some experience and patience.
i have never done nor attempted to do this type of swap so i put info that i thought would help.

 

i knew about the year split for styles of bed but the reason i was asking about the frame is the bed i have for my current project is off a 74 2wd. aslo i think i'd only need a front axle as the truck is an f350 also as for suspension i think the front would be the biggest bear as the rear is just leafs and i may or may not be able to steal the factory lift blocks from my highboy or i could find another set of highboy blocks fairly easilly. and as for finding an existing crew cab 4x4 or frame the issue there comes in i want a long bed and all the crew 4x4s reasonably close to me are expensive as hell and frames are not to be found at all. and in terms of fabrication i'm not afraid of fabbing my own dodads and gizmos or even splicing a frame if need be. the grand question is what is the easiest/ most efective way to do this? i may be a dumb *** here but i think a 1977 crew cab long bed 4x4 f350 with a cummins swap is more epic than a 74 f250 4x4 reg cab long bed with a cummins swap, because well thats just my taste that being said i love my 74 but i have always said a crew cab long bed would be the one thing to get me to part ways with it and i've had it since highschool......

 

your bed should fit if its off a f250 2wd,
the easiest way i think would be to locate a 4x4 f250 for a parts truck, and take all the front end stuff off and mount it to the crew the way it came off the 4x4.

 

My big concern is weather or not the frame up front is the same?

 

Not the same. 2WD frame has the honkin' crossmember under the engine. On a 4wd the crossmember is forward of the engine.

... to be perfectly candid, those asking about 2WD to 4WD conversions on these rigs clearly have not done the most basic of homework.

If you're still thinking, then read the 4x4 conversion links in the Tech Info Compilation.

.

 

copy that, also as far as you know what's the frame situation behind the cab? I have heard that on the f350s some of them had the highboy style rear frame and others had the standard frame. also as for the conversion to 4x4 aside from the cross member what other differences am I looking at frame wise up front? i'm not afraid of fabrication i'd just like to know what i'm getting into (yes I realize it's a hell of a project but a f350 crew cab long bed from the 70's doesn't come along often).

 

To answer the frame width question, it varies from crew cab to crew cab. I am in the process of 4x4 swapping a 79 f250 CC sb, and it still had the 33.5in frame rail width. I have also read of some guys getting the 37.5in frame. To verify, you would need to just crawl underneath and measure yourself. Chances are that since its an F350 long bed, it'll have the narrow frame.

On the front, i just cut up my 76 highboy donor frame, and traced all of the bolt holes over onto the crew cab frame. Then, i bolted all of the hangers and perches on. With the factory wore-out highboy springs, I had to clearance the crossmember, as it was sitting on the pumpkin. But once i installed 6in lift springs off of a 95 f350, i had no clearance problems.

For drivetrain, I used the dana 60 rear and low pinion dana 44 front as they both had the 4.10 gear ratio. This truck is also getting a cummins(just tore out the motor) so i used the divorced Np205 transfer case as i can still utilize the 2wd transmission.

 

I'm building a supercab utility (f150) 2wd into a 4wd.. Not there yet but have started acquiring parts and doing some preliminary work. Feel free to follow along.


1979 2wd f150 supercab utility body... Build? - Pirate4x4.Com : 4x4 and Off-Road Forum

 

Good to know if I get it at least I have an idea of what I need to do

 

as much as it pains me to say it i'm going to have to pass on the crew cab i found...... which really sucks cause how often do you find a rust free 77 f350 crewcab......

 

Rust free? Never. Maybe once every ten years. What the asking price?

 

5K if I recall right

 

https://portland.craigslist.org/grg/cto/5529725151.html

 

Cool truck... 5k is a lot though.