[Barry_R]

The original Ford design had the pump shaft twist like a barber pole & then break once the pump inhaled junk. The pin was stonger than the shaft. We fix that with better drive shafts since an HV pump is harder to spin, and now the pin is the weak point. The pumps used to get locked up from pieces of umbrella valve stem seal and plastic timing sprocket - not many of those in our newer builds.

I have never seen a distributor shaft break from an oversized pin hole. Not any real load up above the gear with electronic ignition, and the gear/pin/shaft area is pretty short and well supported.