If you’re shopping for a Ram chassis cab — the Ram 4500 or Ram 5500 — you’re making a serious work truck decision. These purpose-built commercial platforms give you the chassis strength, GVWR ratings, and cab-to-axle (CA) measurements needed to mount virtually any truck body on the market: flatbeds, service bodies, crane bodies, dump bodies, mechanics trucks, and more.
At Star Truck Equipment in Wharton, TX, we upfit Ram 4500 and 5500 chassis cabs with brands like CM Truck Beds, Norstar, STI, RKI, and more. Here’s everything you need to know to spec your Ram chassis cab correctly.
Ram 4500 vs Ram 5500: Which Chassis Cab Do You Need?
| Spec | Ram 4500 | Ram 5500 |
|---|---|---|
| GVWR | Up to 14,000 lb | Up to 19,500 lb |
| Payload Capacity | ~6,500–7,000 lb | ~9,500–11,000 lb |
| Engine Options | 6.4L HEMI Gas or 6.7L Cummins Diesel | 6.4L HEMI Gas or 6.7L Cummins Diesel |
| Rear Axle | Dual rear wheel (DRW standard) | Dual rear wheel (DRW standard) |
| CA Lengths Available | 60″, 84″, 108″ | 60″, 84″, 108″ |
| Max Body Length | Up to ~16 ft flatbed | Up to ~20 ft flatbed |
| Best For | Service bodies, flatbeds, utility bodies | Crane bodies, heavy service, dump, mechanics trucks |
| Towing Capacity | Up to 23,000 lb (5th wheel/gooseneck) | Up to 31,210 lb (5th wheel/gooseneck) |
Key decision rule: If you plan to mount a crane, run heavy tool storage, or haul significant payload on the bed, step up to the 5500. For standard flatbeds, service bodies, and medium-duty utility use, the 4500 handles most applications with better fuel economy and lower upfront cost.
Cab-to-Axle (CA) Measurements: The Critical Spec
The cab-to-axle (CA) measurement is the distance from the back of the cab to the centerline of the rear axle. This number determines what body lengths fit your chassis and is the most important measurement when ordering a truck body.
- 60″ CA — Fits bodies up to about 9–10 ft. Common on regular cab configurations. Good for compact service bodies, short flatbeds.
- 84″ CA — The most popular configuration. Fits bodies from 9 ft to about 12–14 ft. Works for most standard service bodies, flatbeds, and crane bodies.
- 108″ CA — For longer bodies (14–20 ft flatbeds, extended service bodies, dump bodies). More common on the Ram 5500.
Rule of thumb: Body length = CA measurement + approximately 24–30 inches. Always verify with the body manufacturer for exact overhang specs before ordering.
Best Truck Bodies for Ram 4500 Chassis Cab
Flatbed Bodies
The Ram 4500 with an 84″ CA is a popular base for 9–11 ft aluminum or steel flatbeds. Top choices for Ram 4500 flatbeds at Star Truck Equipment:
- CM Truck Beds — ER, RD, TM, and SK flatbed models. Steel construction, multiple rail heights. The CM ER is a top seller on Ram 4500 84″ CA configurations.
- Norstar — SD, ST, and AM flatbed models. Known for heavy-gauge steel and clean finish. Popular with Texas ranchers and contractors.
- Bedrock — Diamond and Granite series. Powder-coated steel with bolt-together construction. Good fitment on Ram 4500 chassis.
Service Bodies
The Ram 4500 is a solid service body platform, especially for electricians, plumbers, HVAC techs, and general contractors who need organized tool storage without going full heavy-duty:
- RKI (Rawson-Koenig) — Manufactured in Houston, TX. Steel service bodies with deep compartments. Great local support and lead times.
- CM Service Bodies — Heavy-duty steel, multiple compartment configurations. Available in 9 ft and 11 ft lengths to match Ram 4500 CA options.
Best Truck Bodies for Ram 5500 Chassis Cab
Crane Bodies
The Ram 5500 with 84″ or 108″ CA is the preferred platform for crane body applications in Texas oilfield and utility work. The higher GVWR supports crane mounting weights without overloading the chassis:
- STI Crane Bodies — Purpose-built crane body + Tiger Crane combo packages. Reinforced subframe, outrigger-ready design. The top choice for South Texas oilfield operators.
- RKI Crane Bodies — Houston-made crane body platforms. Multiple crane size options, competitive lead times.
Mechanics Trucks
For field mechanics, ag equipment repair, and heavy construction, the Ram 5500 with 108″ CA is a strong base for mechanics truck bodies:
- STI Mechanics Trucks — Full mechanics truck configuration with compartment systems, crane integration, and generator mounts. Built for the Texas workload.
Diesel vs Gas Engine: Which is Right for Your Ram Chassis Cab?
Both the 4500 and 5500 come with a choice of 6.4L HEMI gasoline or 6.7L Cummins diesel:
- 6.7L Cummins Diesel — The overwhelming choice for commercial users. More torque for heavy towing and payload, better long-term fuel economy under load, longer engine life. If you’re doing this for work, get the diesel.
- 6.4L HEMI Gas — Lower upfront cost, simpler maintenance. Acceptable for lighter-duty applications where the truck isn’t being pushed hard daily.
Ready to Build Your Ram Chassis Cab Work Truck?
Star Truck Equipment in Wharton, TX specializes in Ram 4500 and 5500 chassis cab upfitting for contractors, oilfield operators, ranchers, and commercial fleets across Texas and Louisiana. We carry flatbeds, service bodies, crane bodies, and more — all professionally installed at our Wharton shop.
Call us at (979) 532-1486 to discuss your Ram chassis cab build, get a quote, and schedule installation. We serve the greater Houston area, Victoria, San Antonio, and all of South Texas.