Dorman 674-990 Exhaust Manifold

Dorman 674-990 Exhaust Manifold for Select GM SUVs

Dorman 674-990 is a cast iron exhaust manifold engineered to match the fit and function of the original manifold on specified vehicles. It includes the gaskets and downpipe hardware needed for a complete exhaust manifold repair on select 2006-2007 Buick Rainier, Chevrolet Trailblazer, Chevrolet Trailblazer EXT, GMC Envoy, Isuzu Ascender, and Saab 9-7x applications.

Key Features

• Cast iron construction for durable exhaust service
• Natural finish with irregular port shape
• Includes heat shield
• Includes gasket and seal components for the repair
• Mounting hardware included
• Direct replacement for select GM-platform SUVs

Detailed Description

This Dorman exhaust manifold is built for vehicles that need a replacement manifold with the correct fit, port layout, and mounting points. The design follows the original equipment form for the listed applications, helping restore proper exhaust routing on 2006-2007 Buick Rainier, Chevrolet Trailblazer, GMC Envoy, Isuzu Ascender, and Saab 9-7x models, plus 2006 Chevrolet Trailblazer EXT. Part number 674-990 is a practical choice when the original manifold is cracked, warped, or leaking at the flange or gasket surfaces. This part cross-references 101545 and 12587310 for the same application.

What It Helps Repair

• Exhaust leaks at the manifold or flange
• Cracked or warped original manifold housings
• Noise from leaking exhaust gases near the engine
• Failed gasket sealing at the manifold connection
• Corrosion-related exhaust sealing issues

Installation Notes and Tips

Verify engine and vehicle application before installation. Clean the cylinder head and mating surfaces thoroughly, and inspect the flange area, studs, and fasteners for wear before assembly. Use the included gaskets and hardware during installation, and confirm proper alignment of the manifold, heat shield, and downpipe connection. For search relevance, this exhaust manifold is commonly sought as a replacement for 2006-2007 Chevrolet Trailblazer and 2006-2007 GMC Envoy exhaust manifold service, as well as 2006-2007 Buick Rainier applications.

Quality Assurance

Dorman manufactures this manifold to match original fit and function on the specified vehicles. The cast iron construction, included heat shield, and complete repair components support a straightforward OE-style exhaust manifold replacement.