[Rick Parker]

I checked the plug wires, and the plugs they were all OK, one wire needed to be adjusted to fit tighter on the plug terminal. Popped off the distributor cap and found the remains of burned dieletric grease on the tip of the rotor and on each brass terminal inside the cap. I cleaned it off and verified that the rotor was making contact with the center button (which it had been). The rotor and cap are both in good condition having logged about 300 miles.
I removed the rotor and realized the flyweights were not moving freely, they were binding on the pivot pins. There was also evidence of a minor bit of corrosion on the springs and their anchor pins too, then I remembered I had blown an upper radiator hose last fall and in never opened the distributor to dry it off. There was that sticky filmy feeling (dried coolant) on the flyweights and the black pads they rest on. So I removed them and cleaned everything with a little stainless wire brush, bead blasted the flyweights clean, lubed them up and put it back together with new springs. Resynced the carbs and off I went. With the mechanical advance working properly the throttle response was back as I remembered it. Life is good. Thanks for your suggestions.