Heater Core1969-1972 Full-Size Chevy Blazer, GMC Jimmy1967-1972 GM Full-Size Truck, Suburban1970-1972 GM VanAluminum Tank/Core8 5/8 (.625) in. x 2 in. x 6 in.5/8 (.625) in. Inlet3/4 (.750) in. OutletSold Individually JEGS 76020 heater core is for GM trucks originally equipped without factory A/C. A new core will increase thermal performance by dispersing heat into the interior cabin for proper heater and defroster functionality.