Base timing. Really ?

That's a pretty small grind though. I ran that cam in a basically stock '69 383 with a DP4B and 750 vac sec "back in the day" and it idled at 13", 650 rpm or so. Probably could have been tuned for more.
My current 312/.652 ([email protected]) in a 451 wants even more idle advance than the 27 I'm giving it, but still only makes 8" at 1200 rpm. So I can't use the can to pull in more advance.
I do have it connected to manifold vacuum because the cruise is 15" and I drive it on the street most of the time. Doesn't have any effect on the idle timing. Also there's no ported vac on my current carb anyway :)