Dorman 674-278 Exhaust Manifold - Left

OE-Style Exhaust Manifold for GM Trucks

Dorman 674-278 is a cast iron exhaust manifold built to match the fit and function of the original part on specified Chevrolet and GMC applications. It includes the manifold gasket and downpipe hardware needed for a complete exhaust repair on the left side.

Key Features

• Cast iron construction for durable exhaust service
• Natural finish with square port shape
• Direct replacement design for specified left-side applications
• Includes gasket and flange hardware for the repair
• Mounting hardware and seal components included
• Cross-references 651268 and 14050233 for the same application

Detailed Description

This Dorman exhaust manifold, part number 674-278, is engineered for Chevrolet C10, C20, C30, K10, K20, K30, K5 Blazer and GMC C1500, C2500, C3500, K1500, K2500, K3500 applications listed below. It is a left-side cast iron manifold with a square port design, made to restore proper exhaust routing and sealing on 1981-1986 GM trucks and SUVs. The package contents support a complete repair with the manifold gasket, flange, studs, nuts, and washers included.

For buyers searching for a left exhaust manifold for 1985-1986 Chevrolet C10 or a replacement exhaust manifold for 1983-1984 GMC K1500, Dorman 674-278 provides an OE-style solution for the specified vehicles. It is also listed for California emissions configurations on select 1985-1986 Chevrolet and GMC Suburban and K-series models with 4-hole notes.

What It Helps Repair

• Exhaust leaks at the manifold-to-cylinder head sealing surface
• Cracked or warped original cast iron manifold
• Broken or corroded downpipe connection hardware
• Noise from escaping exhaust on the left side
• Failed sealing components during manifold replacement

Installation Notes and Tips

Verify engine-side port shape, left-side placement, and emissions notes before ordering. This manifold is listed for specific 1981-1986 Chevrolet and GMC truck and SUV applications, including select California emissions versions. Inspect the cylinder head surface, exhaust flange, and fasteners during installation to help ensure a proper seal.

Quality Assurance

Dorman manufactures this manifold to match original fit and function on the specified vehicles. The cast iron construction and included sealing and hardware components support a complete exhaust manifold replacement for the listed Chevrolet and GMC applications.