28* initial timing for a 318? How can that be?

I want to come back to this and give some more accurate numbers in Vixens timing. I knew I was close but I wasn't right on it. This morning I got 24 initial with vacuum can disconnected and hose pinched off. Then I got 34 total around 3000 RPM, so that's 10 in the distributor just like I welded and filed for. With the vacuum can I get 40 at idle so we're pulling in 16 with the vacuum can. Idle is "around" 850-900 with the can attached or not, although you can hear a difference when the can has vacuum on it. The cam is pretty big so it doesn't idle very smoothly. lol