I can't pin down a particular valve. Sometimes intake, sometimes exhaust. And I can't pin down a particular set of circumstances except warmed up at high speed- most of the time. A couple weeks ago, after the warm engine valve sticking scenario had run its course, the symptoms went away for most of the remainder of a 100 mile 40-50 mph trip to the salvage yard. Just enough to give me some false hope. I appreciate the honest feedback about this from you all. Dave

1946 Chevy pickup, 1948 Chevy suburban, 1950 Chevy pickup, 1952 GMC pickup, 1957 Chevy pickup, 1939 Chevy pickup