What do I need to look for when determining which fuel pump I need?

Engines of the same series are frequently serviced with more than one fuel pump type. Visible differences between the pump may be the cover inlet or outlet or the separator ring position.

The cover position or separator ring position are determined as follows:

The angle between the rocker arm and the fuel inlet is expressed in terms of clock position. Place pump with rocker arm in the 12 o’clock position. Observe the relationship of the fuel inlet to the rocker arm. This position is the clock position of the pump. Examples of this in the outline drawing shows that if the fuel inlet is at position "A", it is considered a 6 o’clock pump, if at position "B", a 3 o’clock pump, and at position "C", an 8 o’clock pump.