[tubman]

To clarify the carburetor situation. The earlier (circa 1940) and 8BA engines use almost identical Holley model 94 carburetors. A lot of people can't tell the difference and confusion reigns. In 1949 ('48 in trucks), Ford went to a post-style distributor that used a specialized advance mechanism they called "Load-a-Matic". This distributor has no mechanical advance capability and relies solely on vacuum signals from the carburetor for advancing the spark. A special version of the Holley 94 was developed that supplies that specialized signal through a port about half way up the backside of the carburetor. If you don't have that special version, the distributor advance will not function. Simply connecting the distributor advance line to manifold vacuum will not work, as it supplies the wrong vacuum signal to the distributor.

Most people that are not using strictly original engines in their old Ford's usually want to change the carburetion system to multiple carbs or maybe a 4 BBL. It should be noted that updated carburetion systems will not work properly with the "Load-a-Matic" distributor, requiring it to be replaced. The usual replacements are an old Mallory dual-point intended specifically for these engines or an updated SBC distributor reworked to fit the flathead. These have a regular mechanical or vacuum over mechanical advance mechanism.