Exhaust manifold for flathead Ford don't know the year.
I can't find it now but seem to recall an ad showing a factory dual exhaust set of manifolds for the 8BA engine. Some type of "police interceptor" option for the Mercury engines. My 52 Merc has 8BA (with stock single exhaust) in the manifold part number.Maybe after market, dual exhaust.
Did Ford ever make a dual exhaust for the FH?