360 Flywheel and torque converter

Factory 360 LA did not use a flexplate counterweight. Ever. They were weighted on the torque convertor.
Ok good to know. The 3 available at Rock auto have two different sizes, none are 11 inch. Not sure where they're measured from. But two of the 3 are 10" (measured from bolt circle) or 10.625 outer diameter. And the one liner is 12" outer diameter. Curious does the size of the flexplate outer diameter even matter?