I get the Gov spring, but what does the AFC spring do? Where does the govenor spring go? Im looking to buy a 3k spring.

 

The governor springs are installed on the outboard side of the injection pump right beside the fuel shutoff linkage. You take the cover off the side and bar the engine to get to them - there are a couple of threads on this around here somewhere.. Anyway, the AFC spring controls pre-boost fueling