distributer cap mods?

According to don the goverment forced everyone to run vaccum advance off of ported vaccum to increase exhaust tempatures for less emissions in the air.
But anyhow, i'm pretty sure this is a vaccum leak, because like i have already said the symptoms are the exact same as before when it had a vaccum leak around the intake.
Last time i cleaned the heads and the intake, i used a very fine sqaure piece of sand paper and i lightly sanded all the old gasket material off of the intake and the head.
I would love to have it checked with a straight edge, but i do not have one, and this is my only vehicle at the moment. But i will do my best to check it out, maybe have a friend take me to a shop who has a straight edge to get it checked out. I would hate to have to buy a new manifold, this one is basically brand new and its 300 bucks for a new one.