Slightly embarrasing question . . . My 1975 Plymouth Valiant is dieseling. Some of the things I am checking are the spark plugs, distributor cap, and rotor. I made a diagram to make sure the correct spark plugs connect to the correct distributor cap towers. However, I forgot to diagram which side the part which looks like a large vaccum cap with a whole in it goes. The clamps are such that I can clamp the distributor cap in with the rubber part on the left or the right. Can someone please tell me which way I should clamp it back in? Thanks so much!!