Chevy Super Tall Block Black Crab Cap Distributor Low-Profile, Tall Block Racing Distributor MSD IgnitionCrowning this distributor is MSD's own Crab Cap! This cap incorporates spark plug style terminals for a better connection and grip to the plug wires while providing excellent clearance since plug wires exit the side of the cap The housing features two optional O rings at the bottom that improve oil control by preventing oil pressure loss. Also, a small oil bleed hole located in the base sprays oil on the distributor and camshaft gears to prevent