The Factory Service manual lists that cranking compression on a 440 should be 110-150 with the engine warm. I have headers and my plugs aren't too hard to get out and in, but with the headers hot (which they will be while the engine is warm) its impossible not to burn my hands or arms, even if I wear gloves. I tested mine just for giggles, and got 125-130 on all cylinders, how much higher do you think it would be hot?

Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street