Ford's 302 was first manufactured in 1968 and was installed in the Mustang by the middle of the 1968 production year. The 302 was generally considered to be a reliable engine and straightforward to work on due to its simple design and small physical size. Like all engines, the 302 must periodically be tuned up for it to operate at its most efficient. A critical part of tuning up the engine is having the correct specifications.
The 302 was equipped with model BF-32 spark plugs. The spark plug gap, meaning the distance between the plug's two electrodes, was .034 inches.
Within the 302's distributor is a single set of ignition points. This distance between the tips of the points was .021 inches. The dwell angle, meaning the length of time that the tips of the points remain open, was between 30 and 33 degrees.
The correct ignition timing mark is 6 degrees before top dead center, as indicated by the numbered lines on the edge of the harmonic balancer.
Idle speed must be measured when the engine is warm. If the Mustang has an automatic transmission, the correct idle speed is 550 revolutions per minute. If equipped with the manual transmission, the speed is 625 revolutions per minute.
Compression refers to the air pressure within a cylinder when the piston is at the top of that cylinder, as measured in pounds. The factory compression rating was 150 pounds.
Fuel pump pressure refers to amount of pressure the fuel pump delivers to the carburetor. The factory fuel pump produced between 4 and 6 pounds of pressure at idle.
