Ford M-400 Parts & Accessories

Ford M-400 Parts & Accessories

The Ford M-400 was a medium-duty motorhome chassis produced from 1973 through the late 1970s, specifically engineered for Class A motorhome builders who needed a longer wheelbase and higher GVWR than the standard F-series pickup-based chassis of the era. It used a purpose-built commercial ladder frame with a front-mounted 400 cubic-inch M-block or optional 460 cubic-inch 385-series V8 engine, a front-control cab layout, and a rear-drive axle rated for the weight of a Class A motorhome body. Manufacturers including Winnebago, Coachmen, and Holiday Rambler used the M-400 as a basis for their mid-1970s motorhomes, and surviving examples are still in service with owners who maintain them for seasonal travel. This collection provides the drivetrain, chassis, and brake components that keep M-400 motorhomes running reliably.

Popular Upgrades

M-400 maintenance and upgrade projects center on the 400 M-block or 460 V8 engine, with Edelbrock Performer intake manifolds, Holley 600 to 750 cfm carburetors, and Pertronix Ignitor electronic ignition conversions that improve reliability and reduce maintenance frequency on these high-hour engines. Motorhome-duty brake upgrades including front disc conversion kits and rear drum rebuild hardware are high-priority items for any M-400 that has accumulated significant mileage on Florida highways and campground approaches. Transmission cooling systems and auxiliary oil coolers help manage the thermal loads that motorhome-duty operation places on the C6 automatic transmission and the 400 or 460 engine.

Performance and Handling

The M-400 motorhome chassis uses a heavy ladder frame with solid front and rear axles appropriate for Class A motorhome weights, and the suspension was tuned for ride comfort under loaded conditions rather than handling agility. Leaf spring replacements with correct-weight-rating units are the most important suspension maintenance item, as original springs sag with age and reduce the chassis's ability to maintain proper alignment under full motorhome weight. Steering stabilizer additions from Safe-T-Plus or similar motorhome-specific suppliers improve straight-line stability at highway speeds, an important comfort and safety upgrade for long-distance travel.

What engine is in the Ford M-400 chassis?

The Ford M-400 was primarily equipped with the 400 cubic-inch M-block V8 that shares its basic architecture with the 351 Modified but displaces more via a longer stroke, producing strong low-rpm torque suited to motorhome loading cycles. The 460 cubic-inch 385-series was available as an upgrade in higher-capacity M-400 configurations, and it provided additional reserve power for mountain grades and heavily loaded motorhome bodies. Both engines accept the same Edelbrock and Holley carburetor and intake upgrades designed for the 400 M-block and 460 families.

Where do I find parts for a Ford M-400 motorhome chassis?

The M-400 uses Ford commercial truck components that overlap extensively with the F-series and E-series truck parts catalogs from the same era, and most mechanical items can be identified by cross-referencing the Ford master parts catalog for the specific model year. Brake hardware, wheel bearings, U-joints, and transmission components are all shared with other medium-duty Ford truck platforms of the mid-1970s and remain available through this catalog. Motorhome-specific vendors who specialize in Class A chassis hardware can assist with components unique to the M-400 body mounting and utilities integration.

Why These Parts Fit Right

Parts in this collection are verified against M-400 chassis specifications for the 400 M-block and 460 V8 applications to ensure compatibility with this commercial motorhome platform rather than standard F-series truck fitment. Suspension and brake components are rated for the elevated GVWR of the motorhome chassis, which differs from typical pickup truck applications. Fast shipping gets your M-400 motorhome road-ready without unnecessary waiting.

Explore our exhaust systems for 400 M-block and 460 manifold and exhaust options, browse suspension components for motorhome-duty leaf spring and steering stabilizer hardware, and check our air intake systems for Edelbrock and Holley carburetor and intake upgrades.