Ford 8Ba heads with horizontal thermostat surface, when made? 8.27K viewsNovember 21, 2016 0 thefordbarn November 21, 2016 0 Comments Most 8BA heads had the t stat surface parallel to the head surface but this set has the t stat surface parallel with the intake surface. When were these made? What are they worth? 1 Answer ActiveVotedNewestOldest 0 DMarv Posted November 27, 2016 0 Comments Are you inquiring about factory cast iron heads or aftermarket aluminum heads? Register or Login Offenhauser Sales Corp, 5300 Alhambra Avenue, Los Angeles, CA 90032 Phone: (323) 225-1307