Everything You Wanted to Know About Ignition Advance

Couldn't get my big cam 318 to idle without manifold vacuum.

On ported it wanted to over heat at idle and shake the livin crap out of the whole car. had to run it at 1100 rpm to idle in gear at a light.

Put an adjustable can and a travel stop on the rod. The can started pulling in at 6" vac and was all in at 12". The rod stop limited idle vac advance to 24*.

Ran great after that and idled at 800 rpm. still shook a bit more than a bit but I could idle in gear without stalling, over heating or chirping the tires when I put it in gear.