Two timing marks on balancer, which one to use?

[1972Blaze]

I have been working on getting my truck tuned properly. Today I started working on checking some things with my mechanical advance and timing at WOT. As I was playing with the distributor position for the first time I saw two lines on my balancer. Can anyone look at this setup and tell me which line I should be using?

[toolboxchev]

Part of figuring this out will have to have you bring your #1 cylinder to TDC. When you have that established you should be able to tell which mark to use.

Sorry I can not automatically give you an answer. You may also have to pull your distributor cap and make sure it is pointed at the #1 plug wire terminal. We have run across many a engine set up improperly.