Tim, let me throw another wrinkle in here. I have seen several pix of stock 1953 216 ci engines with a single clamshell horn mounted on the intake manifold. The pair on the firewall was an accessory, as I understand it, and is treated as such in the Chevy Accessory Manual.
One of these pictures does look like a possible manifold mounting bracket. But that's the one marked "Lo." Maybe someone knows about these? Thanks!
Harry
