[Rick Parker]

The rotor has a small round post and a square one, 180 degrees apart to provide correct fitament. The corresponding holes are near the posts that anchor the before mentioned springs. Put a dab of dielectric grease on the center carbon post in the cap, see if it transfers to the spring blade on the rotor when the cap is fit, if not bend the blade slightly until grease does transfer indicating positive contact.

This entire operation is best done with the distributor out of the engine and mounted carefully in a vise. Be sure to mark or orient the location of the rotor and reinstall in exact same location. The replacement is somewhat tedious and would be very difficult with the distributor in the engine.