72 360 first start question

BTW, for that cam it has 4 degrees ground-in advance, and is a symmetrical cam. So, at equal lift at intake and exhaust, the damper zero mark (slit) should line up at 4 degrees BTDC.

Is your damper one without any imbalance with with imbalance? It is pretty obvious and should be the imbalanced one, with a large area of weight removed or added.. The damper being so far off is certainly of concern, and making your own marks may work but just adds to the inaccuracy if not done with a lot of precision.