Mercury - Quicksilver Exhaust Manifold Gasket Exhaust System Seal Marine-Grade Composite 33395. Overview. A strong seal in your exhaust system keeps your engine quiet, efficient, and protected. The Mercury Marine 33395 Quicksilver Exhaust Manifold Gasket is built for V8 MerCruiser sterndrives and inboard engines made by General Motors, including 283, 305, 350, and 377 CID models. Made from durable marine-grade composite material, this gasket is designed to handle the heat, vibration, and pressur