2000 Duratec Compression Check

I get a misfire code of 306 after the car has run for a while then sits for about 45 minutes. Once I start it again and let it idle for a few minutes, the idle gets worse and eventually begins misfiring on cyl. 6. I've swapped the coil with the one next to it to see if the code would follow the coil swap. Nope! Still 306! I replaced the plugs. Still have a problem. I used my MAC compression tester, but it would only screw in about 1 1/2 turns. Not enough to seat it completely. I checked all cylinders.
cyl.

1 180psi
2 165psi
3 180psi
4 180psi
5 175psi
6 120psi

The car has 94k miles. Idles pretty smooth, but it sounds as a miss from the exhaust. When the Check Engine light comes on or flashes, it runs very rough and sets code 306.... I'm tempted to recheck the compression using the correct thread adapter.

Has anyone pulled the heads on a 2000 Duratec? If so, what is the torque sequence, the torque setting, and is there any difficulties dealing with the timing chain? I need to find a manual for this car ;-)

Thanks,
Sparky