Need help tuning a 273.

Well I'm not sure how to set the timing with my setup. The manual suggested 10 B for a 1965 stock 273. But mine is not stock.

Here are a couple of questions and sorry if my english is a bit weird, I’m from Sweden 

The vacuum hose for the distributor can hook up to two places on my edelbrock carb. Not sure which one to use, but I believe it used to be to the right side if standing in front of the car. What’s the difference?

At what rpm should it idle when I set the timing and what timing would you suggest?