Cylinder Head Intake And Exhaust Lifters Compatible With : 2001 - 2007 Chevrolet Silverado 2500 HD Classic, 3500 8.1L / 496 CID OHV 16 Valve, Vortec, Vin G - 2000 7.4 L / 454 CID - 2001 - 2007 GMC Sierra 2500 HD Classic, 3500 V8, 8.1L / 496 CID OHV 16 Valve, Vortec, Vin G - Mercury Marine 454 Gen IV And V V8, 8.2L / 502 CID OHV 16 Valve, Mercruiser Chevrolet Engine V8, 7.4L / 454 CID OHV 16 Valve