"Wouldn't the tape that I get depend on the diameter of the harmonic balancer that I have???"

Yes, and it also depends on the relationship of the damper (not balancer) outer ring to the actual position of the number 1 piston. There is an elastomeric material between the inner hub and the outer ring that can allow the outer ring to slip in relation to the hub. When this happens, you can't time the motor by ANY method and be correct.