The Stovebolt Site Forums The Shop Area Engine Shop 1949 Chevrolet 3100 216 cu.in. initial timing question?

Just looking for some clarification on the correct initial timing mark on the flywheel of a 1949 Chevrolet 3100 with a 216 cu.in. engine. I have seen various posts where some members say to use the BB as the TDC timing mark and some say to use the U/C as the TDC timing mark. I am just looking for clarification.

Tim