Cast iron bell #'s??

acpat said
look on the mounting surface to the trans. only two cast iron bellhousing that I am aware of are 68 10inch and 64-65 early A body nine inch flywheel

Well I took a scotchbrite pad to the trans mate surface and no joy. Is there another way to tell between the 9 and 10 inchers? If I posted some pics could any of guys tell the difference?

Thanks

CE