@flathead31coupe ,4.5" dampener. Circumfrence is pi times d. Divide result by 360 to get distance of one degree. Multiply that by the 28 degrees you want.
I came up with a mark 1.099 (roughly) from tdc. Make a mark 1 3/16ths(and a scoshe more) . You will be within a degree either way.
Then, use your advance/retard mark to adjust from there for more or less timing.