Okay, I mounted the Powermaster 9100 up. I have the 15/16" cneterline to flexplate gear. Now the .062 min clearence is just barely met. Powermaster suggestted I mount upside down. That did not work (will not bolt up and clear flexplate gear!!). I hate to tear into the new starter to add the ring spacer as advised on their web site. A 1/16 drill bit clears most gear to gear places as flexplate is moved but this starter has a protruding center hub that has slightly less than 1/16" clearence to ring gear. Still have more stuff to hook up b-4 firing engine.