Reply to "How should I be driving my engine?"

Sure, a GM pin would work fine. So would a piece of drill rod staked on both ends. But I really hesitate to recommend drilling out the distributor drive gear pin size. Reason is, the shaft is sometimes hardenable high-carbon steel. I've drilled a few with no problem, and had others that were very difficult. Less risky to just double-pin the stocker.

What can happen is, Mr Ill-Equipped-Owner has a 3/8" hand drill and a set of Indian- or Chinese-made drills of questionable steel from a swap meet or Harbor Freight, that are not very sharp. He drills part-way through the shaft before friction causes the area in front of the cutting edge to heat-treat itself super-hard. Then either the drill's edge goes completely away or breaks. That leaves Mr do-it-himself with an unuseable distributor, on his way to a local machine shop. A pricey carbide drill and a drill press or milling machine with LOTS of cutting oil is the next step to finishing the 'simple' drill job....

If you need to add a new gear, that's another problem. Ford sells them un-drilled and says to not attempt to drill the gear to match the existing shaft hole, but to install it indexed in another position and match-drill both gear & shaft together. Indexing to an existing hole can be done, but it ain't easy; the gears are a press-fit and height is critical. Aftermarket or 460 electronic distributors can have gears the wrong height for some Cleveland blocks.