Model A & B

Ford Garage

Spark Plug Connector Variations

The original A-12275 Model A spark plug connector used from 1928 through mid 1930 was symmetrical about its length and had a rounded end at the spark plug. The length of the connector was 3-1/8" from the center of the plug hole to the end of the fork.

In June 1930 the connector was redesigned in a manner to allow the strips to nest side by side and be cut off a continuous coil, greatly reducing the amount of scrap material in manufacturing. The length of the connector was also 3-1/8" from the center of the plug hole to the end of the fork.

Ford redesigned the distributor in 1932 for the Model B and raised the height of the distributor body relative the the spark plugs. This had the effect of requiring a greater length spark plug connector for the Model B. The length of the connector was increased to 3-5/8" from the center of the plug hole to the end of the fork.

The pic above shows the 1928-30 connector on top, the 1930-31 connector in the middle, and the 1932 Model B connector on the bottom.

The B-12275 connector was released for 1932 production, and the A-12275 was retained for service on the Model A.


Original Model A and B spark plug connectors were made from phosphor bronze, not brass. However, there have been many reproductions and replacements made from brass over the years. There have also been a few Ford script brass connectors turn up, but there is no archive evidence that those are genuine Ford.

Phosphor bronze is an alloy of copper and tin, and in addition to its electrical conductivity has many spring-like characteristics, and resists oxidation. This makes it much better suited for the connection to the distributor body than a non-spring brass connector.


Pictured above is a Model A distributor and Champion 3X spark plugs, showing a Model A connector on the left and a longer Model B connector on the right. Note that the shorter Model A connector is just long enough to reach the terminal on the distributor body, and the longer Model B connector is essentially 'too long'.


Pictured above is the taller Model B distributor and Champion 3X spark plugs. A Model A connector is shown on the left, and a longer Model B connector on the right. Note that the shorter Model A connector is not long enough to reach the terminal on the distributor body.

Note: For modern owners, an important consideration is the fact that most replacement spark plugs are not as tall as the original Model A Champion 3X. Therefore, use of the longer Model B connectors on many Model A's is useful or even necessary.


July 2009