What is the trick to getting the valve cover off a /6 with AC?

It's a 1970 duster. I got the valve cover off, when I swiveled the AC unit to get the belt off, I had just enough room to get the valve cover out. Now it's got some fresh paint drying on it and tomorrow morning I will be able to have everything back together, with new belts, hoses, thermostat, temp sender and antifreeze.