I am new poster, but long time lucker. Trying to figure out if a 302 with factory air conditioning did or did not have a a distributor with the dual diaphram vacuum advance unit. Several sources indicate that only the single diaphram unit was used, but looking at some pretty original examples it seems that at least some have the dual diaphram. The car in question is 155374, build date of April 04, has PS, PB, AC, C4, Swing Away, 3.00 axle. If some of you could checkk out how your car is equipped and share the information it wold be a big help. Thanks