812 top mount fuel pump

I found a top mount fuel pump at Hershey for my Cord.  The rocker arm spring and the lower diaphragm spring are the same length but one has a heavier gage wire.  Is the heavier spring for the rocker arm or lower diaphragm?  Should there be an upper diaphragm spring as in the exploded picture of a similar fuel pump?  The Cord 810/812 parts list has only the rocker arm spring listed and no upper or lower diaphragm spring.