Engine compression

[SoCalSlaughter]

I have a 90' Chevy Suburban V2500 5.7lt TH400 trans. Ive noticed recently a miss while the truck is at idle in park, once its warmed up it seems to go away. I tried to do a compression test but the starter went out.. haha replaced starter last night and havent tried a test again. I tried on cylinder number 2 hooking up my compression tester with my air compressor plugged into it and at tdc and btc I can hear a hiss coming from the exhaust and I rock the rocker arms back and forth making sure they are loose and not pushing down on the valve. Could this be a burned exhaust valve or rocker arm to tight? I did noticed the rocker on the exhaust didnt move as much as the intake valve. Valve job in my future? haha