Bronze distributor shaft gear wear

Ran a bronze gear on several rollers for about 20 years (racing, not significant miles, but a lot of runs) and still good. My experience was on some of the blocks/bushing set ups, was there was more likely a vertical too tight condition that needed to be corrected when the dist was tightened down, than too much clearance. I always fit the dist with the intake off to verify while doing pre-assembly and check that there is enough clearance.