Spectra Premium CU2423 Complete Radiator for General Motors Innovative engineering, manufacturing technology and quality control ensure that Spectra Premium radiators meet or exceed the performance of the original equipment radiators they replace; that extends to all components, including engine and transmission Maximum cooling efficiency No modifications required for proper fit Engineered to last ; Thickness of the product is 1inch. Perfect fit guarantee ; Inlet Size: 1 5/16 inch ; Outlet Size: 1 9/16 inch Inlet Header - 18-7/16 In. x 3-1/8 Inches Outlet Header - 18-1/8 Inches x 3-1/8 Inches