GMC, Chevrolet, Isuzu Radiator - Northern Radiator 238642, Active Radiator Supply Company 580030, 1-800-Radiator 2403364, Reach Cooling 42-10427

The Reach Cooling 42-10427 is an aftermarket aluminum downflow radiator engineered as a direct replacement for GMC, Chevrolet, and Isuzu medium-duty trucks from 2003 through 2009. It cross-references Northern Radiator 238642, Active Radiator Supply Company 580030, 1-800-Radiator 2403364, Serck FLA000856, NAPA NR4210427, and Paccar Parts RAD42-10427TRP, making it straightforward to confirm you have the right part before it ships. This radiator fits the full GMC Topkick lineup - C4500, C5500, C6500, C7500, and C8500 - as well as the Chevrolet Kodiak C4500, C5500, C6500, C7500, and C8500, and the Isuzu HVR and HXR, covering 4.8L, 5.3L, 6.6L, 7.2L, 7.8L, and 8.1L engines. Built with reinforced B-type tubes for improved pressure tolerance, deep extrusion headers that resist vibration and thermal expansion at the tube-to-header joint, folded fin edges for added stability and heat transfer, and thermal expansion cuts that allow the core to breathe through normal heat cycles, this radiator is designed to meet or exceed original equipment specifications. An integrated transmission oil cooler with 18-inch fitting spacing is included. If your Kodiak or Topkick is running hot and you need a reliable, correctly fitting radiator, the 42-10427 is the direct drop-in replacement to reach for.