Chevrolet, GMC Radiator - Chevrolet 20859, Northern Radiator SC239340, Spectra Premium CU2507, Reach Cooling 42-10421

If you're sourcing a radiator for a 1995-2002 Chevrolet or GMC Kodiak or Topkick, Reach Cooling 42-10421 is the aftermarket direct replacement built to get your truck back on the road with confidence. This cross-flow radiator features an aluminum core and plastic tanks, and it comes with an integrated transmission oil cooler - so you're not hunting for a separate unit. It replaces Chevrolet 20859 as the primary OEM reference, and it also cross-references Northern Radiator SC232108, Active Radiator Supply Company 580035, Spectra Premium CU2507, Serck FLA000844, and NAPA NR67217B. Fitment covers the Chevrolet and GMC B7, C60 Kodiak, C6000 Topkick, C6500 Kodiak, C6500 Topkick, C70 Kodiak, C7500 Kodiak, and C7500 Topkick across 6.0L, 6.5L, 6.6L, 7.0L, 7.2L, 7.4L, and 8.1L engines from 1995 through 2002. Reach Cooling engineers B-type tubes with central reinforcement for greater pressure tolerance, uses deep extrusion headers for a stronger tube-to-header joint that resists vibration and thermal fatigue, and incorporates thermal expansion cuts to extend core life through normal heat cycles. When Chevrolet 20859 is what your truck calls for, 42-10421 is the aftermarket answer that installs correctly and performs to OE standards.