Can soneone tell me or point me to a discussion.

I did not find anything in a search

I'm pretty sure they were all 11 inches.

Here's David Pozzi's page.

http://ourworld.compuserve.com/homepages/David_Pozzi/brakes.htm#Converting_Drums_to_Discs

JL8 option brakes came with 11.75 rotors.