Just an observation...
I carry an extra MSD distributor, along with a bunch of other "extra" stuff. When I pressed off the original iron gear and pressed on the new steel gear, it took a lot of pressure to move the gears on the distributor shaft. I mean A LOT. I don't know how much torque it takes to turn the
oil pump at 6K+ RPM but it appears to me that most of the torque to the gear is intended to be applied by the friction fit of the gear on the shaft; not by the pin. Is it possible that those of you who've sheared roll pins may not have a tight enough gear to shaft fit?
Also, I agree with the observation regarding not drilling any more holes than necessary in the distributor shaft. I used the original gear as a fixture to set up the new gear in the Bridgeport, although a drill press could work as well (located the old gear with the hole oriented to the spindle, locked down the table, then clamped the new gear in place), then drilled the hole in the new gear in the same place as the hole in the old gear.
Yeah, so now I'll probably twist off a gear on start-up tomorrow...but at least I have an extra distributor timed and ready to drop in.
Lowell