Compatible with Big Block Chevy® equipped with square bore intake manifold. This product is not created or sold by Chevy®.; Made of strong and durable plastic, these Jaz Products engine block-off kits protect your engine by blocking off open ports to Intake Manifold, Manifold Exhaust ports, Water Pump and Fuel Pumps openings during storage or as a work in progress. These kits prevent dirt and debris from entering various inlets and outlets on your engine. Sold as a Kit.;.