The 2025 GMC Sierra 3500HD is a strong service-body platform — especially the cab & chassis, which is designed from the factory to take an aftermarket body. Whether you are a plumber, electrician, welder or field mechanic, the fitment questions come down to three things: SRW or DRW, cab-to-axle, and how much weight you actually carry.

Which Sierra 3500HD are you starting with?

Configuration	GVWR	Body options	Notes
3500HD SRW pickup	~11,350 lb	Replace bed with 8–9 ft SRW service body or flatbed	Narrower track; easier daily driver
3500HD DRW pickup	~13,000–14,000 lb	9 ft DRW service body or skirted flatbed	More capacity, wider body needed
3500HD Cab & Chassis (56″/60″/84″ CA)	~13,000–14,000 lb	8, 9, or 11 ft service body	Best choice for a true service truck

Cab-to-axle and body length

• 56″–60″ CA — 8 or 9 ft service body. Fits most urban and residential trade work; short enough for driveways and parking garages.
• 84″ CA — 11 ft service body. Choose this if you carry a compressor, a welder, long stock, or need a walk-in style compartment layout.
• On a pickup conversion, the factory 6’9″ or 8′ bed comes off and the body bolts to the frame — confirm your bed length, because the frame length behind the cab is what governs fitment, not the bed you removed.

SRW vs DRW on the 3500HD

Dual rear wheels add roughly 1,500–2,500 lb of usable rating and, more importantly, lateral stability with a tall loaded service body. If you run a crane of any size, a compressor plus welder, or a full plumbing inventory, choose DRW. If your body is mostly hand tools and light material, and you value fitting into tight residential jobs and standard parking, SRW is fine. Service bodies are built in width-specific SRW and DRW versions — they are not interchangeable, so lock this in before ordering.

Body recommendations from our lineup

RKI (built in Houston, TX) is our go-to steel service body for trade contractors who want deep compartments and a proven door system close to home. CM SK gives you a skirted flatbed with service storage when you also need open deck space, and NXG is the value pick when you want a clean steel body without paying for features you will not use. Full lineup on our service bodies page.

Payload reality check

A 9 ft steel service body weighs roughly 1,700–2,200 lb installed. On a 14,000 lb GVWR cab & chassis with about 7,000 lb of chassis, that leaves near 5,000 lb — plenty for most trades. On an 11,350 lb SRW pickup with ~7,300 lb curb weight, the same body leaves under 2,200 lb for tools, material, fuel and crew. That is where guys get overloaded without realizing it. Weigh your current truck loaded; it is the cheapest spec tool you have.

Towing context

A properly equipped 2025 Sierra 3500HD DRW tows up to roughly 36,000 lb gooseneck and 20,000 lb conventional, but a loaded service body eats into that through payload, not the tow rating — gooseneck pin weight rides on the truck. Plan for pin weight plus body plus tools when you pick SRW vs DRW.

Install timeline

If the body is in stock, we typically remove the factory bed (or receive your cab & chassis), mount, wire lighting, install the receiver and gooseneck if requested, and return the truck in one business day. Bring the truck in the morning, drive it home that evening.

Get a Real Quote — Installed, Not Estimated

Star Truck Equipment is at 2507 County Rd 231 in Wharton, TX, about an hour southwest of Houston. We stock beds and bodies from Bedrock, CM, Norstar, NXG, Pronghorn and RKI, and most in-stock installs are done in one business day. Call (979) 532-1486 with your year, make, model, cab-to-axle and wheel setup and we’ll tell you exactly what fits and what it costs installed — or browse current inventory.