Stainless Steel Long Tube Headers for GMC C/K Trucks (1979-1985) 5.0L 5.7L

High-Flow Stainless Steel Long Tube Headers for 1979-1985 GMC C/K Trucks (Squarebody)

What it Does: The Stainless Steel Long Tube Headers replace the restrictive cast iron exhaust manifolds on 1979-1985 GMC C/K Trucks to optimize exhaust scavenging, relieve backpressure, and increase low-to-mid range torque.

The Stock GMC C/K Trucks Exhaust Restriction

Factory exhaust systems on third-generation Squarebody platforms rely on heavy log-style cast iron manifolds. These OEM units feature short, uneven runner lengths and rough interior casting walls that create severe turbulence and high exhaust gas backpressure. Cylinder pairing is poor, preventing natural inertial scavenging between firing cycles. Under load or during heavy towing, this restriction traps exhaust heat near the cylinder heads, slowing combustion chamber evacuation, dulling throttle response, and suffocating the Small Block Chevy (SBC) 305 and 350 engines in their critical mid-range power bands.

The Engineering Solution

Engineered for high-duty cycles, these long tube headers feature smooth, CNC mandrel-bent T-304 stainless steel primary tubing measuring 1-5/8 inches in outer diameter. The tuned runner lengths guide spent gases into merged 3-inch collectors, producing an exhaust scavenging wave that siphons residual combustion gases out of the chambers during valve overlap. Thick, precision CNC-machined cylinder head flanges eliminate the heat-cycling warpage and carbon blow-by common to thin stamped steel or worn cast iron. The corrosion-resistant stainless finish withstands severe thermal stress without degradation.

What's Included

• 2 Long Tube Headers (Left and Right)
• 2 Collector Reducers
• 2 Header Gaskets
• Collector Gaskets
• Mounting Bolts and Nuts

Technical Specifications

Compatibility

• 1979-1985 GMC C1500 Pickup Small Block V8 (5.0L 305ci, 5.7L 350ci)
• 1979-1985 GMC C/K 1500, 2500, 3500 Series Trucks (2WD / 4WD Small Block V8)

Frequently Asked Questions & Fitment Warnings

Does this fit the Squarebody C/K Trucks?

Yes, this is a direct bolt-on fit for 1979-1985 GMC C/K Trucks equipped with the Small Block Chevy 5.0L (305) and 5.7L (350) V8 engines in both 2WD and 4WD configurations.

Are these headers legal for highway use in emissions-controlled states?

No, these headers are designed for off-road and competition use only and are not CARB-compliant, making them illegal for street use in California or states following CARB standards.

The GMC Heavy-Duty Standard

Built for the working truck, these headers provide the structural integrity and scavenging efficiency necessary to generate sustained low-rpm pulling power, cooler cylinder head temperatures, and dependable reliability under heavy hauling and towing conditions.