Performance Radiator with Shroud for GMC C/K Trucks (1975-1978) 4.1L 4.8L 5.0L 5.7L

High-Efficiency Aluminum Performance Radiator with Shroud for 1975-1978 GMC C/K Trucks

What it Does: The All-Aluminum Performance Radiator with Shroud replaces the failure-prone factory cooling assembly on 1975-1978 GMC C/K Trucks to lower operating temperatures and eliminate boilover under heavy load.

The Stock GMC C/K Trucks Cooling Deficiencies

Factory cooling systems on 1970s Squarebody GMC C/K Trucks rely on aged copper-brass cores and mechanical clutch fans that struggle against modern heat demands. Over decades of heat cycling, factory brazed tank seams suffer fatigue cracking, internal passages succumb to mineral scale occlusion, and solder bloom severely impedes thermal transfer. Furthermore, the stock engine-driven fan draws insufficient cubic feet per minute (CFM) at idle and low-speed crawling, precipitating severe heat soak, elevated cylinder head temperatures, and vapor lock when towing.

The Engineering Solution

This performance cooling assembly upgrades the system with lightweight, aircraft-grade T-6061 aluminum construction. The high-density furnace-brazed tube-and-fin core drastically increases convective surface contact, while 100% precision TIG-welded end tanks eliminate leaky crimped or soldered joints. Engineered with an application-specific aluminum shroud and integrated high-CFM electric fan, this unit drives forced laminar airflow across the entire fin matrix regardless of engine RPM, eliminating parasitic crankshaft drag and providing consistent thermal dissipation for both Inline-6 and Small Block V8 powertrains.

Technical Specifications

Compatibility

• 1975-1978 GMC C15 / C1500 Pickup (4.1L 250ci, 4.8L 292ci, 5.0L 305ci, 5.7L 350ci)
• 1975-1978 GMC C25 / C2500 Pickup (4.1L 250ci, 4.8L 292ci, 5.0L 305ci, 5.7L 350ci)
• 1975-1978 GMC C35 / C3500 Pickup (4.8L 292ci, 5.7L 350ci)
• 1975-1978 GMC K15 / K1500 4WD Pickup (4.1L 250ci, 5.0L 305ci, 5.7L 350ci)
• 1975-1978 GMC K25 / K2500 4WD Pickup (4.1L 250ci, 4.8L 292ci, 5.7L 350ci)
• 1975-1978 GMC K35 / K3500 4WD Pickup (4.8L 292ci, 5.7L 350ci)
• 1975-1978 GMC Jimmy / Suburban (4.1L 250ci, 5.0L 305ci, 5.7L 350ci)

Frequently Asked Questions

Does this fit the Squarebody C/K Trucks?
Yes, this is a direct fit for the 1975-1978 GMC C/K Trucks equipped with the 4.1L, 4.8L, 5.0L, or 5.7L engine configurations.

Does this convert the truck away from the factory mechanical fan?
Yes, the integrated shroud and electric fan replace the factory mechanical clutch fan assembly, reducing parasitic drag while delivering superior low-speed airflow.

The GMC Heavy-Duty Standard

Engineered for maximum thermal overhead, this cooling system reinforces your classic GMC truck with the robust durability required for severe-duty hauling, steep mountain grades, and heavy bumper-pull towing.