1967 Corvette 435hp 3904391 finished matching L71 heads A21-23-7

1 matching pair of finished 3904391 square port cylinder heads, which were used on 1967 corvettes with the 427 / 435hp engine option.   Both of these cylinder heads have the identical casting number, 3904391, and adjacent casting dates of  A 21 7, January 21, 1967, and A 23 7, January 23, 1967.   There have been no alterations, modifications, or machine work done to the ports, and there are no cracks or repairs.   Both heads have undergone a complete valve job including new springs, valves, lifters, rods, and retainers, and all required machine work has been done.   These are a finished pair of matching heads, and they are ready to be assembled to an engine. 

     We do have other 3904391 finished heads, with various dates, depending on your needs.