Mallory Dizzy's..??

I have a couple mallory distributors.  The pin for the distributor gear is smaller than the pin for an OEM.  I inquired with Mallory a couple years ago, as to whether it was acceptable to drill the hole larger for the OEM pin, Their tech rep said no problem, and I bought a matched set of Bulltear gears which I never actually ran.  I don't think Bulltear still sells those.  I think the only name brand gears available are the MSD.  Those should be "matched" and some have postulated that MSD was the source of Bulltear gears, which then received a chemical? treatment of their own.  If you have a known good set of OEM gears, safest bet is to swap.  Also, be aware that timing covers can have the distributor location in the wrong place, so a known original timing cover is also the preferred choice.  I believe SC397 has a write up of how to test the distributor alignment for an unknown cover.