The only Ford (460) distributor that really pissed me off, was an MSD billit with a bronze/brass gear for a hydraulic roller cam, it literally would not line up right and fit like crap, went in really hard and came out really hard, ended up talking to MSD and they sent me a new gear and the damn thing went right in......to this day, no clue (had to send the old gear back). I thought it was the hex oil pump shaft that was hanging things up, but couldn't find any problem with that, which is why I replaced the gear (the shaft goes all the way through the gear onto the oil pump shaft.