Moroso 25160 Moroso Chevrolet Big Block Mark IV (w/Conv. Heads) Exhaust Block-Off Storage Plate - Aluminum - PairMoroso 25160 Moroso Chevrolet Big Block Mark IV (w Conv. Heads) Exhaust Block Off Storage Plate Aluminum Pair Exhaust Block Off Storage Plates, BBC Mark IV Conventional Heads, Constructed out of Aluminum, Pair, Fits: BBC Mark IV with conventional cylinder heads A convenient way to keep engines sealed up from foreign objects during storage or when an engine is being painted Durable aluminum construction, come as pairs