New SFI magnum Flex plate coming soon.

Jadaharabi said
On the LA motors using the B&M plates doesn't the 904 use a smaller diameter flexplate than the 727 so that the starter clears the flexplate.

This was my understanding for 904 as well, but I don't have a 904 torque converter to mock it up. LA or Magnum just changes the balance weight, and 904 or 727 changes the diameter. I could be wrong.