Edelbrock heads on a 340 with KB243 pistons

Other than the obvious typo at the beginning [minimal clearance .005] they seem to like a lot of clearance on their motors. I also did a little researching and found that Jegs sells a marine head gasket that is .049 compressed height in stock for about $35 each and Cometics at .051 for $78, the Cometics then jump up to .060