2wd Frame to 4x4 Frame conversion

[RedneckTexan]

I have a 68 F-100 that I would like to convert to a 4x4. I got a 76 F-150 4x4 truck Frame that I would like to swap the body on to, However, the donor truck is a l.w.b. and the 68 is a s.w.b. What could I do to convert my 68 truck frame to a 4x4 frame

[hardtailjohn]

Do a search on here...someone's already doing that or something quite like it...
JH

[72hiboy4x4]

toss the '68 cab on there and build a flatbed for it!
No worries!

[RedneckTexan]

That's a good idea, but I'd like to keep the stepside bed on it.

[averagef250]

Trying to use a 2wd frame is a bad idea. Isn't it Zakt? That's using his 2wd crew frame and converting to 4x4? He's doing tons of custom fabrication to make it work and going with a very large lift to eliminate interferance issues with the front crossmember.

If you don't have really good fab skills and the right equipment, I'd strongly recommend starting with the 4x4 frame, or just buying a complete 4x4 to fix up. If you do have the means, then the way I would do it would be to put your '68 F-100 cab and front clip on the later frame, do some real careful measuring and cut the rear half off of both frames. Then weld the bumpside shortbed rear section onto the late model front section at a place where they are the same width.

This is not easy, there are very critical alignments that need to be spot on or the truck won't be worth much. You don't need to box the frame where you cut it, when I cut a frame down, I do it at the straightest point possible and have some A36 structural 3/16" plate broken into "C" channel that's the exact size for a hammer tap fit into the inside of the frame rails and with legs that are an inch long. I full pen buttweld the frame halves together with 6011 rod, grind the inside flush and tap a foot of the "C" channel into place on each side, welding all the way around it. I then plate the outside of the framerail with another piece of 3/16" plate 4"X12". Use a needle scaler generously to shot peen the welds and relieve the surface weld stresses.

6011 is not "strong", but it is VERY "tough". Everyone wants to run for the 70, 80 or 90 series rods for frame repairs not relizing how much frames flex. 70K+ tensile welds do not flex, they crack when they're pushed past thier limits.

[RedneckTexan]

This maybe a stupid question, but is there any way to move the rear end foward and chop the extra frame off the rear

[averagef250]

Anything is possible. The later 4x4 frame is not straight like the bumpside frames. It widens about 6" from the rear of the cab to bumper. The frame is also humped over the axle. The bed is made to fit the contour of the frame. Though I don't really know how flaresides are, I've never owned a ford flareside before.

Converting a 2wd ford to 4x4 is not easy. There are tons of parts that are different from 2wd. For the best results, start with a 4x4.

[RedneckTexan]

Thanks for the advice average250, when I get some money, I'll probably just buy a 67-72 s.w.b. 4x4 frame.

[zakt]

The conversion is overwhelming so I would also recommend a 4x4. Im not so lucky though I wanted the crewcab longbed and no 4x4 with that till what the 80's. Mine is even more complex since Im using different leaf springs than the 67'. Im using 85' F350 springs which are longer with a 3" width so everything needs re-drill on hangers and re-centered so the axle will be center on the wheel well. Then of course the front I have the 85' leafs which are longer and wont put the axle in the center so need to be custom made. I do have a front 78' F250 clip to possibly put the springs/crossmember in if necessary.... Also lately I cut out the 2wd gear box and have to move that to the front by the core support (have that 78' F250 4bolt box). I will be putting a 95' F350 460 EFI in it and that now will have the E40D, BW1356 so have L&L motor mounts for the 2wd to use then a custom clock ring to turn the transfer case to fit in the frame rails.....it goes on and on .....so in summary get a 4x4 frame Here is the 67' with the rear 12" springs and 33" tires.. then decided to tear it all apart and start from the ground up

THEN:




NOW: (filling old leaf hanger holes (will look pretty )

[RedneckTexan]

Hey zakt, would it be possible to shorten the dent-side frame from 133" to 115" Did you see trucks! last weekend? they shortend a 65 cheby l.w.b. to a s.w.b. and it looked pretty strong (for a cheby)

BTW, SWEET CREW DUDE!

[zakt]

I actually have a 95' F350 frame that is 6" longer than my 67' so could just put the body on but....like averageF250 said you have to do alot to cut and weld it correctly. I dont mind the time with the 67' as my time doesnt cost me the same as paying someone So, yes I would think you could cut it shorter. I have even looked around and trying to find someone to do it is next to impossible because of the liability.

Todd

[averagef250]

Glad to hear you're still making progress on the truck Todd!

On the subject of the '95 frame... I've seen bump and dent fords on '80 and up 4x4 frames and the results are not pretty. You basically end up with a 5" bodylift to get the old body to even clear the frame. Atleast the one I saw that was done and driving.

As far as getting a crewcab longbed highboy goes... If I had to do it, I might start with a standard cab longbed 4x4 frame and stretch it in the middle where the factory did. The frame is perfectly straight and even there and should even be the same dimensions as the 2wd frame so you could cut out the piece you needed to lengthen it.

I cut my first frame down because I had to, I bought a chevy K30 when I was 18 without a bed on it thinking it was a longbed. Nope. It was a 12 foot cab-chassis, so much for my calibrated eye. Bought the bed, put it on and found, to my surprise, a foot between the cab and bed.

Frames are not really hard to work on, there really isn't much liability if you use good fabricating practices. If you can fill holes in your frame, I'd put money on you being able to stretch a 4x4 frame.

I measure a hundred times, cut once and it usually works.

[72hiboy4x4]

I lengthened a '66 crew cab short box once, cause I wanted a 12' flatbed on it.

Whacked the crew cab SWB frame where the frame rises to clear the REAR axle, Then took another '66 LWB truck and cut it right where it rises to clear the FRONT suspension.
The frames were the same (or really close) and I ended up with a 4' stretch with only one seam to weld.
I wish I would have finished that truck...got the frames together then lost my job and the shop I had at the time....