Gentlemen,
I'm attempting to put together some parts for a frame swap on a bump side. I'd really like to swap out the drive train when I do it. I've been looking for a 04-10 manual truck.
As you can immagine most of these trucks are DRW or CC DRW. I'd like to keep the bed from the bump side.

My question is about frame width. I can I swap a SWR axle onto a DRW or CC DRW frame? I'm assuming not easily. My hope is to keep factory ford suspension and adjust the length.

Any thoughts?

 

The srw and dually frame are the same width, the cab and chassis model is only 34 inches in the rear, this is in superduty lingo, I'm not sure about the bumpside widths.

 

Shaun,
That is extremely helpful.
I'll be looking for a non- cab chassis as I need a single wheel rear. It will be easier to swap a SRW axle onto a DRW frame than on a CC frame.

This is unfortunate, since I'm currently looking at a manual CC that a tree fell on the cab.

 

Not only is the frame width different, the axle housing itself is shorter than a non cab and chassis truck. You can make it work but the spring mounts have to be cut off and remounted.

 

To be clear, you want modern frame, modern axles, and modern suspension, with legacy bumpside body on top?


The original 1967-1972 bumpside frame, aft of cab, for the entire length of the bumpside bed, was 33.5"

The original 2004-2010 Chassis Cab frame, aft of cab, for the entire length of bed area frame, was 34.1"

The original 2004-2010 Super Duty Pickup frame, aft of cab, for the entire length of the bed, was 37.x"

Note that the model year ranges are limited to only the model years that you identified in your post.

This does not mean that model years before or after what is stated above do not have same frame widths.

However, this DOES means something VERY IMPORTANT that you should always remember with a bumpside.

Bumpside frame widths are narrower than Super Duty pickup frame widths, which are 3+" wider than bumpsides.

Therefore, you might actually be better off with a chassis cab donor frame (depending on length).

The chassis cab's narrow frame width and axles are a closer match to the bumpside's narrower frame width.

The pickup frame width and axles will be 3" wider than the frame that was originally under the bumpside.


F-350 Chassis Cabs are in Single Rear Wheel (SRW) also. The frame is same width as DRW chassis cabs.

Ford has produced SRW narrow frame regular cab chassis cabs from 1973 through 2025.

Frame widths of dentside 1973-1979 SRW 140" WB camper special pickups were 33.5", like your bumpside.

Frame widths of denside 1973-1979 140" WB Chassis Cabs, DRW or SRW, doesn't matter, were 33.5" also.

Frame widths of 1980-1997 bullnose, bricknose, and OBS regular cab chassis cabs were 34".

Frame widths of 1999-2025 Super Duty Chassis cabs, any cab style, any wheel base, SRW or DRW, are 34"

Frame widths of Ford Full Size Pickups of any genre newer than 1977 not mentioned above are 37.x" wide.


The frames do not vary in width between SRW and DRW within the chassis cabs.

The frames do not vary in width between SRW and DRW within like genres of pickups newer than 1980.

The variation in frame width is between pickups (37") versus chassis cabs (34").

The chassis cab frame width is closer to matching the bumpside's (33.5") original frame width.



Adjust the length of what?

The suspension? The length of the leaf springs? The space between leaf spring hangars? Or the length of the frame?

Whatever you are doing will not be easy, but it will not be impossible either.

For frame to body fitment between generations, there is more than just length to consider. The middle dip in the frame to lower the step in height at the cab area, and the cab mounting positions on the cab floor coordinating with the outriggers on the donor frame, are some of the fabrication challenges that lie ahead, to match the cab height with the bed height.

But setting length and undulations aside, and focusing on width, which is the title question... you need not worry about your donor 2004 chassis cab frame rail width being an issue because the chassis cab was a DRW. The frame width at the rear axle is the same as if the donor chassis cab came from Ford as an F-350 chassis cab SRW.

F-350 Chassis Cabs are different and distinct from F-350 Box Deletes.

F-350 Box Deletes don't have a bed, but have a wide pickup frame.

F-350 Chassis Cabs don't have a bed, but have a narrow chassis cab frame.

 

I love this forum.
Y2KW57, thank you for your time.

 

if not mentioned....the last time I was leaf spring hunting I learned that the leaf lenths are different on cab and chassis vs pickup.

 

I had 94 f350 springs on my 79 f150. I just had to smash them a little. Used the truck 20 years that way hauling wood. Didn't ride too bad either.

I have a buddy with a bumpside cab on a 2000 f250 frame. 7.3 with a zf5 or zf6 he drives every day. I can get any info you may want from him