Jim Brierley does it again!!! when I checked for an intake vacuum leak yesterday I did it the old fashioned way of squirting a little oil around the surface and see if it changed speed. After EVERYTHING else has failed I decided to pull the manifold a few minutes ago and look more closely at the gasket and the mating surface. As I pulled the manifolds off something fell on the floor. It was a big chunk of the intake manifold. I t was on the underside of the intake manifold hidden from view. Problem solved--a manifold intake leak like the master suggested. Thanks to everyone for all of your helpful suggestions. Now I can sleep tonight!