Just one little problem with that fix- - - - -GM starters don't use a Bendix drive. Ford, yes, Chrysler, yes, but the GM starter drives are positively engaged into the flywheel ring gear before the starter motor ever begins to turn. The mechanical linkage of the stomp starter extends the gear into the flywheel, then the copper contacts make to start the motor turning. Ditto on the solenoid-type starters used on the automatic trans models, and all of the engines after the stompers were discontinued. The solenoid linkage has the gears firmly meshed before the motor contacts engage. The overruning clutch on the GM drive is probably slipping, since the engine is only turning some of the time. Peening on the outside of the sheet metal housing will simply make the drive gear lock up in both directions, and probably overspeed the starter armature and throw the windings out of it. A new starter drive is cheap insurance.
Jerry