Stovebolt distributor housings do not run bushings. The steel shaft runs in the cast iron housing, and there is a phenolic plastic thrust button and a spring under the grease cup that pushes the shaft sideways to compensate for housing wear. Once runout gets excessive, which creates variations in point gap and dwell, the distributor was supposed to be discarded and replaced. It's possible to ream the housing for bushings top and bottom to correct for wear, as long as the shaft isn't worn out of round also. A better fix is to bore the top of the housing for a Torrington needle bearing, and press a thin hardened steel collar over the shaft, ground to a minimum clearance fit to the bearing rollers. That's a job anyone who has the unmitigated gall to call himself a machinist can do pretty easily. Then the lobes on the cam can be checked with a dial indicator to assure they all have the same angular accuracy and lift. Then tweak the centrifugal advance to original specifications and be sure the vacuum chamber works properly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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