8.1L, 496 CID GM Vortec Marine Engine Cylinder Head. For Port Side (Left side) F. This product data sheet is originally written in English. For Port Side (Left Side) F. 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 complete with valves and springs. Complete with valves and springs. Replaces casting #’s: 162. 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 (Left Side) F 8.1L, 496 CID GM Vortec Marine Engine Cylinder Head. Replaces Mercruiser #900-8M0091709 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.