Ford Super Duty Cab-to-Axle Guide | F-250 F-350 F-450 F-550 Truck Bed Fitment

Ford Super Duty Cab-to-Axle Guide: F-250, F-350, F-450 & F-550

One of the most common questions we get at Star Truck Equipment in Wharton, TX is: “What size flatbed fits my Ford Super Duty?” The answer depends almost entirely on one measurement: cab-to-axle (CA). Get the CA right and your flatbed, hay bed, or service body will look great, tow straight, and pass DOT inspection. Get it wrong and you’ve got an overhang problem on your hands. This guide covers every Ford Super Duty configuration — F-250 through F-550 — so you know exactly what fits.

What Is Cab-to-Axle (CA)?

Cab-to-axle is the distance from the back face of the cab to the centerline of the rear axle. It’s measured in inches and is the primary spec used by truck body manufacturers to determine what bed length fits your truck. The general rule is:

Maximum bed overhang past rear axle = 6 inches (DOT practical limit). So your bed can be no longer than CA + 6 inches without creating compliance and handling issues.

On a pickup truck, CA is measured on the factory chassis. On a chassis cab (F-450, F-550), CA is specified by Ford during the order process — this is why chassis cab CA length is a critical spec to confirm before purchasing a truck body.

Ford F-250 Super Duty Cab-to-Axle Chart

Cab Style	Box Style	Wheelbase	Approx CA	Max Recommended Bed
Regular Cab	Long Box (8 ft)	137″	~56″	7.5–8 ft flatbed
SuperCab	Long Box (8 ft)	158″	~60″	8 ft flatbed
Crew Cab	Short Box (6.75 ft)	158″	~50″	7 ft flatbed (verify clearance)
Crew Cab	Long Box (8 ft)	176″	~66″	8.5–9 ft flatbed

The F-250 is a ¾-ton — payload is tighter than a 1-ton. Keep bed weight under 600 lbs (SRW) to maintain a healthy payload budget. Aluma aluminum flatbeds are the best choice for F-250 SRW operators who want maximum payload with a full-size flatbed.

Ford F-350 Super Duty Cab-to-Axle Chart

Cab Style	Box Style	Wheelbase	Approx CA	Max Recommended Bed
Regular Cab	Long Box (8 ft)	137″	~56″	7.5–8 ft flatbed
SuperCab	Long Box (8 ft)	158″	~60″	8 ft flatbed
Crew Cab	Short Box (6.75 ft)	158″	~50″	7 ft flatbed (tight — verify)
Crew Cab	Long Box (8 ft)	176″	~66″	8.5–9 ft flatbed

The F-350 SRW is the most popular flatbed pickup in Texas. The Crew Cab Long Box is the ideal configuration — the ~66″ CA accommodates a 9-ft flatbed cleanly, giving you maximum bed space without overhang concerns. For DRW F-350, you have even more payload margin to run heavier beds like the Bedrock Granite 9G or Bradford Built.

Ford F-450 Super Duty Cab-to-Axle Chart (Chassis Cab)

The F-450 is a chassis cab truck (Class 4, GVWR 14,000–16,000 lbs) ordered directly with a specified CA length. Ford offers multiple CA options:

CA Option	Wheelbase	Recommended Body Length	Typical Application
60″ CA	~141″	8–9 ft body	Light service body, flatbed for general trades
84″ CA	~165″	10–11 ft body	Standard service body, hay bed, extended flatbed
108″ CA	~189″	12–13 ft body	Full service body, crane-ready body, long flatbed

The F-450 84″ CA is the most common spec for service body and flatbed installs. It accommodates a 10–11 ft body comfortably and works with every major brand we carry — CM, RKI, STI, Bedrock, Norstar. The 108″ CA is the choice for crane body builds — Tiger Crane + STI or RKI setups on the F-450 108″ CA are a proven Texas combination.

Ford F-550 Super Duty Cab-to-Axle Chart (Chassis Cab)

The F-550 is Ford’s heavy-duty Class 5 chassis cab (GVWR 17,500–22,000 lbs). It’s the premier single-axle crane truck platform in the Ford lineup:

CA Option	Wheelbase	Recommended Body Length	Typical Application
60″ CA	~141″	8–9 ft body	Compact utility, light service body
84″ CA	~165″	11–12 ft body	Full service body, crane body (mid-range), hay bed
108″ CA	~189″	13–14 ft body	Crane body (heavy), extended service body, lube truck body
132″ CA	~213″	14–16 ft body	Lube trucks, mechanics trucks, extra-long crane builds

The F-550 108″ CA is the standard spec for full crane truck builds in Texas — Tiger Crane (8,000–15,000+ ft-lb capacity) + STI or RKI crane-ready service body. The F-550’s 17,500–22,000 lb GVWR allows you to load the crane, body, tools, and fuel simultaneously without weight violations. Used extensively by oilfield service companies, utility contractors, and pipeline operators across South Texas and Louisiana.

SRW vs. DRW on Ford Super Duty Trucks

SRW vs. DRW affects both payload capacity and bed mounting:

SRW (F-250, F-350 SRW): Standard rear axle width. Most 84″-wide flatbeds mount cleanly. Payload is the binding constraint — keep beds under 600 lbs for maximum cargo flexibility.
DRW (F-350 DRW, F-450, F-550): Wider rear axle. DRW-specific bed mounts or fender notching may be required on some models. More payload capacity — handles heavy service bodies and crane builds without payload concern.

Matching Your Ford Super Duty to the Right Body

Here’s a quick decision guide based on what you’re hauling:

Ranching / Hay Hauling: F-350 Crew Cab Long Box SRW or DRW + 8.5–9 ft CM, Bedrock, or Bradford Built hay bed
Gooseneck Towing / Contractor Flatbed: F-350 Crew Cab Long Box + 8–9 ft CM RD or Norstar SD
Trades (Electrician, HVAC, Plumber): F-350 SRW or F-450 60″ CA + CM SB or RKI service body
Oilfield / Pipeline Crane Work: F-550 108″ CA + Tiger Crane + STI or RKI crane-ready service body
Light Crane / Utility: F-450 84″ or 108″ CA + Tiger Crane (3,000–6,000 ft-lb) + STI or RKI service body

Get Measured and Quoted in Wharton, TX

Star Truck Equipment installs truck bodies on Ford Super Duty trucks from F-250 through F-550 every week. We serve Texas and Louisiana commercial buyers from our shop in Wharton, TX — with easy access from Houston, Victoria, San Antonio, and Corpus Christi.

📞 (979) 532-1486 — Call today. Give us your truck’s year, cab style, and CA length (or bring the truck by) and we’ll quote the right body for your operation.