[69 longhorn]

Sorry to hear about your troubles,& I would be aggravated also. Your mechanic evidently missed something......you can hear an improperly shimmed starter 1/2 a block away! The difference in yrs on the block is not where the problem is coming from.....its the difference in machining tolorances from the factory,& if the flex plate isnt chewed up, shimming should solve the problem....that should have been part of the job. As another thought,I have seen the rear bushing go bad for no apparent reason on a rebuilt starter,so its up to the mechanic to sort it out.a good mechanic will make it right. good luck......69 longhorn.