I have zero advance when checked under timing light throughout the rpm range. I suspect i need a new vac advance unit for the distributor. I bought what was advertised as a NOS B5S 12370A on Ebay. The unit came in the correct box but was considerably greater in diameter than what I took off the car. With the replacement unit installed, it pulled way too much advance, so i suspect that this is the wrong vac unit. I have called and checked around and have not found another source for the unit. Anyone know a source? BTW, i am trying to cure a stumble that kicks in just when i open the throttle off idle. I figure i cannot even attack that issue until i ensure that the timing is correct.

Jim

Jim H