I started at 12. The vacuum gauge showed it wanted more. I have one of those mechanical advance plates ordered you mentioned in another post. I will check that out and some lighter advance springs later. My 2 barrel carb needs a kit so I didn't want to crowd things. I had a Hell of a time getting out the #56 Autolite plugs. I thought I was going to break them off in the head and they are the wrong heat range for a 70 318. It's much happerier now and so far so am I. LOL