Dorman 674-426 Exhaust Manifold - Right

Dorman 674-426 Exhaust Manifold for Right Side Repair

Dorman 674-426 is a standard replacement exhaust manifold engineered to match the fit and function of the original manifold on specified vehicles. Built from ductile cast iron with a metallic gray finish, it is made for direct repair on the right side of select Chevrolet and GMC trucks and vans.

Key Features

• Ductile cast iron construction for durable exhaust service
• Rectangle port shape with an 8-hole mounting pattern
• Oxygen sensor port included
• Collector port diameter: 1.8
• Tube wall thickness: 0.125
• Standard replacement grade for OE-style fit and function
• Includes gasket and downpipe hardware for a complete repair
• Package contents: 1 exhaust manifold

Detailed Description

This Dorman exhaust manifold is built for direct replacement on the right side of select applications, including 2014-2018 Chevrolet Silverado 1500, 2017 Chevrolet Silverado 2500, 2018-2020 Chevrolet Express 2500 and Express 3500, and 2018-2020 GMC Savana 2500 and Savana 3500. It also serves 2014-2018 GMC Sierra 1500 right-side applications. The manifold is precision-engineered to align with the original part’s fit and function, helping restore proper exhaust routing and sensor placement. Dorman 674-426 is a practical OE-style solution for Chevrolet Silverado, GMC Sierra, and full-size van exhaust manifold replacement needs.

This part cross-references 12631813 for the same application.

What This Part Helps Address

• Cracked or warped exhaust manifold housing
• Exhaust leaks at the manifold-to-cylinder-head interface
• Broken or damaged oxygen sensor port area
• Restricted exhaust flow caused by manifold damage
• Noise from leaking exhaust on the right side of the engine

Installation Notes and Tips

Verify right-side fitment by year, make, and model before installation. Inspect the cylinder head sealing surface, downpipe connection, and oxygen sensor threads during repair. Because gasket material and downpipe hardware are included, confirm all related components are in serviceable condition before assembly. Follow factory torque specifications and exhaust service procedures for the vehicle.

Quality Assurance

This manifold is manufactured as a standard replacement part and is precision-engineered to match original fit and function on specified vehicles. Its ductile cast iron construction supports dependable exhaust service in demanding truck and van applications.