Dang, I picked up a engine miss :(

Just before I left for a car show in Dubuque, I picked up a miss at idle. The car ran good over and back but had a shake at idle. When I got home I messed with the carb but no change. I hooked up my cylinder balance analyzer to cancel cylinders and #4 is weak. I switched plugs and wires but no change. Tomorrow I hope I have time to pull the valve cover and see if there's a broken spring or a adjuster that backed off. A bent pushrod would be nice although I haven't pushed it past 4,000 rpm. I hope it's something simple. Wish me luck.
Toolmanmike