sometimes you have to look at how far down the shaft is pressed into the gear. it's possible for the distributor and gear to go solid if the shaft is too high in the gear and the distributor tightened down. see if you have another gear, iron or bronze, to compare against. also if that may be the case it should show up at the collar on the bottom of the distributor housing. i've had issues where i thought the shaft was pressed too deep, so it may be possible for it not to be pressed deep enough.