Timing and Idle Speed

What should my car be idling at? 69 Polara with a 383. Came with a 2 barrel and single exhaust. I put on a dual with a 4 barrel Edelbrock. Don't know if that matters or not.

Also, the timing marks... I cannot read the marks. I can see the hole, but cannot make our the marks beyond that. The edges of the thing with the marks, is that ten degees out? 5 degrees? Twenty?

Thanks.