F450 Superduty vs. F350 Cab and Chassis Frames
 

Does anybody know if the F450 and F350 cab and chassis have similar frames?
F250 and F350 pickups frames are the same.
F350 Cab and Chassis frames share the same front frame section back until where the frame narrows up to 34" wide (pickups stay 37.5" wide).
The front frames between pickups and the Cab and Chassis are the same so that engine swapping is a breeze. The crossmember is the same, just the individual motor mounts change. Good planning Ford!
I'm wondering if the F450's are the same as the F350 Cab and Chassis, just with the heavier axles?
F450's are cheap around here because last October Mass DOT started cracking down, any rig over 10k gvw MUST be DOT inspected. Many F450's (and the short wheelbase F350 cab and chassis @ 11k gvw) are up for sale cheap because they can't pass inspection. I'm just wondering if I could pick one up just for the frame, and expect the extra F350 axles/running gear to bolt up. I'll take measurements in the morning, maybe some F450 owners could also post up some measurements.
Some of these F450's with the rollback tow truck bodies have some long wheelbases - perfect for building a 14' or 16' flatbed and moving lots of Hay!

I'd be keeping the F-Superduty axles and suspension too, they are way stronger than the F350 stuff, and with the D80 rear you also get rather massive disc brakes. If memory serves me right from my last trip to the U-Pull-It the frame rails on the F-Superduty are both thicker and taller than the cab-chassis F350s, but the their horizontal layout should be the same as they use the same cabs and their rear sections are at 31.5" (or thereabout) by industry standard.

88-98 F450 frames are a completely different animal compared to a F350 of the same vintage. thicker and taller are the start, forged spring brackets, and the ability to shred sheetmetal at 500k on the odo. every one of mime pulled apart their cabs at the welds due to the pounding from the cracks in the pavement. Should you choose to use F450 components, especially the springs, get yourself a kidney belt. you will need it for the beating you will receive. this chassis cemented Ford's dominance in the 15k GVW market until 1999.

Thank you for the replies. I was way off on my thinking! The F-Superduty chassis sounds VERY solid.
I was thinking that the F450 chassis is generally longer, for use in the rollback trucks. I was thinking that I could put F350 axles (Dana 60/10.25) under the F450 to make a long wheelbase F350 4x4. Frames aren't alike, so that idea is shot.
Anybody know about frame lengthening? I see Frame Lengthening or Shortening featured in the big truck repair shop advertisements. Maybe a big truck repair shop could lengthen an F350 frame for me?

Around here a common sight is a long wheelbase F350, with a van style box, and they are used to deliver potato chips. I couldn't say how long they are, but suspect that it is a 12-14' box. They are 350's, not superduty (or F450) trucks.

You need a rear axle from a cab-chassis F350, this will have the same frame width as the F-Superduty. I know for sure the F-Superduty springs and hangers can be bolted to an F250 or F350 frame and they fit the axle spring perches perfectly, so I can't see why you wouldn't be able to do the opposite and swap the axles under the springs. For the front it may be just a matter of pulling the I-beam axle off and bolting a D60 in, but due to the spring arch you'll end up with a pretty high front end, think of it as factory lift kit, but you'll have to do something in the rear to match that, maybe 4" factory F350 4x4 blocks between the F-Superduty springs and the new axle will do the job...


Anybody know about frame lengthening? I see Frame Lengthening or Shortening featured in the big truck repair shop advertisements. Maybe a big truck repair shop could lengthen an F350 frame for me?[/quote]
They should be able to, just as long as they can find suitable C-channel steel. I'd still try to use the F-Superduty frame tho, it's a safer bet IMHO.

They can roll straight frame sections to match your frame, and to glove it too.
I have an F350 frame stretched for an old 2 car hauler bed. The bed iirc is 21 feet long, so yes you can do it.

can I cut the frame in my 05 F350 142" WB to 137" WB to install a regular pick up bed?

ya, you would just have to take the driveline down to have it cut down and balanced as well.

and im sure you would have to drill a few new holes for the bed bolts.

what kind of shops do that?

Around here several the machine shops all do work like that for the oil and gas companies.

They always seem to need trucks longer or with different bed or axle configurations than what the factories offer.

i have a 2000 f350 cab chassis. will a pick up bed fit on it?

yes it will

Cab and chassis frames are 34" wide, and have flat frame tops.

Pickup frames are 37.5" wide and have a hump over the rear axle.

So you can put one on it, but it is not going to be a drop on and bolt down install.

You will need a few spacers for the bed cross member to frame space, which may not let the body lines line up.
For bolt locations, either make brackets to use the stock bolt locations or drill new holes.