Sierra 18-5396 Mercruiser Distributor Cap V6 Thunderbolt IgnitionSierra high-quality engine parts are designed to meet OEM specifications. Includes gasket; Fits GM V-6 engines with Thunderbolt IV & V HEI Ignitions; Interchangeable with: GLM; 71500; Mallory; 9-29400; Mercruiser Stern Drive; 815407A2; 13753A2; 11108A3;