[Roger Shultz]

The answer to my two problems turned out to be resolved with a valve adjustment and likely the main problem was the O2 sensor. After the valve adjustment, the O2 sensor was disconnected as a test and the car ran strong, no hesitation when "cool" nor around 3000 RPM as I initially reported. I intended to change the O2 sensor myself however since it appeared never to have been changed in 135K miles, not only were the catalytic converter shield bolts a mass of rust, the O2 sensor ultimately was frozen in place. I took it to PowerTech in Rockaway, NJ who solved that problem and the car now runs very well.

Thanks to all who responded with ideas and to Pelican for hosting this wonderful resource!