Flexplate installation issue.

We thought by grinding the starter a little it would fit... However it does not. This flexplatr was on another friends engine with a 727.. but my transmission is a 904. Can this be the issue? And if so then which flexplate should I use for my application with the 904?
Your starter looks wonky
Have you tried the friends starter?
I mean the relationship inside the friends bellhouse would have been the same. If it worked for him with his starter, then his starter should work in your bell.images?q=tbn:ANd9GcTCv9a28Sh0CFfqAlLi30fOa6ul8h4QgflEdIhkqHkMXhPpDmf7.jpgimages?q=tbn:ANd9GcRHOBEH_NObX68fZlbIyijdE9C_bTHpoHfaLoyBp50G1nJmQkExdg.jpg