How do I measure flywheel to see which one I have??????

When I got the setup it was behind a '69 steel crank 440 in a duster. He gave me a small block bellhousing to go with trans. The flywheel does have 130 teeth. I guess it does help when you don't have to guess what I am talking about. It was all in my head but just didn't make it here. Lol. I haven't seen any numbers on the flywheel but the clutch that came with it had a 10.5" disc. Oh ya, it is going on a steel crank 340.