to check starter alignment make a simple tool on a lathe. Make it to to barly slip over front nut. Remover starter motor and push in tool to check alignment. To profile the legs of your starter mount to your front cover turn a piece of 3" pastic pipe to mount front cover. hot glue 3 or 4 pieces of emery cloth to front cover and spin in lathe. hold nose of tool in chuck with starter base on tool legs facing cover. sand legs agaist spinning front cover. mount cover on motor. remove emery cloth and put masking tape on where legs meet. Put tool through starter mount. slip nose of tool over nut and trace legs with fine pen. center punch with sping loaded punch .
after mounting slip in tool. It should slide easy over front nut.
if it is off some you can reverse the tool to "tweak " the front cover.