Need Help Harmonic Balancer

You will probably need to use a ‘71+ balancer and then put your own timing tape on it once you’ve found TDC.

Just thinking out loud though, you already have a ‘71 up timing cover on that engine. If you haven’t already found a ‘67 timing cover and water pump the less expensive and time consuming path may be to buy a new radiator, rather than covert everything you have to fit your current radiator. Especially if that radiator hasn’t already been tested.