GMC G25 Van Parts & Accessories

GMC G25 Van Parts & Accessories

The GMC G25 is the three-quarter-ton full-size van designation used through the 1970s and into the early 1980s on the G-body platform, the GMC equivalent of the Chevrolet G20 van and the mid-range option between the half-ton G15 and the one-ton G35 in the full-size van lineup. The G25 was built for buyers who needed more payload capacity than the G15 offered, including high-roof conversion van companies, ambulance upfitters, and cargo operators who regularly loaded the van near or at its half-ton-plus payload limit. Factory engines were the same inline-six and small-block V8 options available across the G-body lineup, with the 350 cubic inch small-block being the dominant choice for any G25 used for payload duty or conversion van applications. The G-body platform's broad parts availability and simple mechanical architecture make it an accessible restoration and upgrade target for owners working on these vans today.

Popular Upgrades

Front disc brake conversion kits from Classic Performance Products are the most important safety upgrade for any G25 van returning to regular service, with the three-quarter-ton van's higher payload weight making improved braking even more critical than on the half-ton G15. Edelbrock Performer intake manifolds and Holley 600 to 650 carburetors on the 350 small-block are the foundation of any G25 performance or drivability build, and electronic ignition kits from Pertronix address the points maintenance that factory ignition systems require. Power steering pump and gear rebuild kits restore the easy, predictable steering feel that makes the G-body van pleasant to drive despite its size, addressing the wear that develops in high-mileage hydraulic steering systems.

Performance and Handling

The G25 uses heavier-rated front coil springs and rear leaf springs than the G15 to support the higher payload rating, which affects shock absorber selection since three-quarter-ton rated dampers are the correct replacement for maintaining the appropriate load balance. Monroe Load-Leveler rear shocks or helper spring inserts like SumoSprings are popular on G25 vans used for regular cargo hauling, providing better load stability than standard replacement shocks on a van that regularly carries near-maximum payload. The G-body van's front suspension ball joints and control arm bushings accumulate wear in proportion to the number of loaded miles, and fresh Moog components restore the precision and quiet operation that defines a well-maintained G25.

What is the payload capacity of the GMC G25 compared to the G15?

The G25 three-quarter-ton van was rated for approximately 1,500 to 2,000 pounds of payload depending on the engine and axle package, compared to the G15's approximately 1,000 pound rating, making the G25 the appropriate choice for operators who loaded their vans to the top of the cargo area with dense cargo. The heavier rear axle and spring package in the G25 are the primary mechanical differences from the G15, and these components require G25-specific replacement parts rather than the lighter G15 hardware. Engine, front suspension, and most cab components are shared across the G15 and G25, so parts for those systems cross-reference freely between the two vans.

Are G25 and G20 Chevy van parts interchangeable?

Yes, the GMC G25 and Chevrolet G20 van of the same model year share identical mechanical specifications including the frame, axles, engines, suspension geometry, and brake hardware, making parts cross-referencing between the two brands universally applicable for mechanical components. Exterior styling differs in the grille, badges, and some trim pieces that are brand-specific, but all mechanical repair and performance upgrade parts are interchangeable. Using both the G25 and G20 as search terms when sourcing parts maximizes the available catalog and helps locate harder-to-find restoration components.

Why These Parts Fit Right

Parts for the GMC G25 are verified against the G-body three-quarter-ton van platform with engine and payload rating fitment clearly noted. Differences between G25 and G15 specifications are flagged for rear axle and suspension components where three-quarter-ton specific hardware is required. Most in-stock parts ship same day or next business day.

Explore related resources in the exhaust systems collection, the suspension parts catalog, and the air intake systems section.