8.1L, 496 CID GM Vortec Marine Engine Cylinder Head. For Port Side (Right Side). This product data sheet is originally written in English. This is a BRAND NEW. Marine cylinder head for all 8.1L/496 Standard & HO Vortec marine engines. For the port (left side) side of the motor. This is an aftermarket replacement cylinder and comes bare, without with valves and springs. Complete with valves and springs. Replaces casting #’s: 162. Will use 2.19 intake & 1.88 exhaust valves. Mercruiser part #900-8M0188298, 900-8M0091709. Volvo Penta part #3808518. Listing and template services provided by inkFrog. Track Page Views With. For Port Side (Right Side) 8.1L, 496 CID GM Vortec Marine Engine Cylinder Head. This is a BRAND NEW marine cylinder head for all 8.1L/496 Standard & HO Vortec marine engines made from 1992-newer. Marine Engines 4 Less.