I think I recall having same issue after water pump R&R. Too many years, that model no longer here. I'm not sure the arm with slot is on the correct bolt.
I did want to ask, If the fuel lines from pump to carb are new... Where did you get them?
Someone measured their '72 with factory AC and the alternator arm is 5 1/4" from hole to slot. This was a kit for a non-AC car that I salvaged bits and pieces. May have to cut and weld this one to the right length. I will research which water pump hole it should go into.
