Vacuum advance needed for cam break in?

35 is pretty slow no load.

I also time the distributor while it's on the stand. If I want 40 or 45 or whatever I'm usually within a degree or two of that when it fires.

Never drop the distributor in timed at TDC. They sort hard and again, slow timing kills parts.

Maybe so, but I've never seen exhaust overheat at 35 "or so". I agree to try to drop the distributor in "a little" advanced. Usually, it'll pop right off.