Looked for vacuum leaks - found none. Put fresh gas in it and that helped a little. Then I pulled the valve cover and did a very unscientific and imprecise thing. I backed off each of the intake valves about 1/4 turn on the rocker adjusters. This seemed to make the most difference. I didn't have the Racecarl guide to valve adjustment handy so I put the valve cover back on and drove it. Now an ever so slight hesitation still exists and the motor occasionally pops and farts back through the carb when motoring along at 45 in 4th gear.

I'll wait till I have some time in the coming week to see about a proper valve adjustment.