Pertronics ignition - initial settings? - 273 V-8

[MVRCorp]

So I just mine and I'm just wondering about a good street setting. We have a choice of distributor options, mechanical spring advances and advance limiters (12-16-20 degrees). it also has a vacuum advance. Now the box has a setting for COA (crank offset angle) This is a setting for the second shot to the plugs. I'm hearing 2-4 degrees. Does anyone have this set-up? What do you think I should start with? Oh, I have the idle advance at 10 degrees with the vacuum hose removed and plugged.
Jim

[illfish]

Run 12 degrees advanced and 36 total.

[PureGTS]