My '66 (200 Engine, 3 speed, autolite 1100 carb) has been running flawlessly for years. Just recently, starting running like SH*T. Very bad idle, stalling and rough running at low rpm. At high RPM, all was pretty good. So I figured maybe a vacuum leak.
I removed the carburetor and voila !! This is the spacer to intake manifold gasket - it is total disintegrated (top photo) - almost non existent. I know gaskets can wear out but I've never seen this before.
I had to use a razor blade to scrap off the remains, clean up the surface, and then laid a new gasket on the surface (bottom photo). Car runs like new again. Interestingly, this happened only to the gasket between the spacer and intake manifold and NOT the carb to spacer gasket. I wonder if this is from the ethanol in gas nowadays and if so, I wonder if any gas station sells gas without ethanol?