Reply to "Double pinning distributor gear?"

The stronger pin allows somewhat larger debris to pass before the pin breaks
or the distributor driveshaft wraps up like a barber pole. One common form
of debris is from the OEM umbrella seals which disintegrate after 35+ years.
The 351C pick up has a bypass hole in the pick up screen which allows relatively
large debris to pass. The pickup from a 351M/400 truck engine does not have a
bypass hole so is more effective at blocking debris and will bolt on in place
of the 351C pick up. See:

http://www.bacomatic.org/galle...Onews17of38.jpg.html

Dan Jones