Harmonic balance out of spec?

I adjusted the rockers and pushrods this past weekend and while doing so, a question came to mind. While positioning the rotor on the distributer at TDC for number one cylinder, I noticed that the timing mark was way off. At a point 'before' the scale which is mounted on the engine. I suppose the timing mark on the balancer should have been on the "0" mark Correct? I know these things can wear out and loose their calibration, as it's the 2nd one I have on this truck. Purchased from Damper Doctor less than 5 years ago. Short of replacing it again, can a reliable second mark be made with paint or something to use for the reference point? Since the maintenance work, it has been wanting to choke itself off and I'm thinking the timing and carb settings may need to be completely checked and adjusted. Thanks in advance!

80 GMC 1/2-ton PU
305 V8
2WD
w/ac