Well that it should be doing... the engine needs air in order for it to burn the fuel, so that is what it should be doing. I have heard that a bad coil and spark wires will cause the lack of power, all mopars have this problem with bad wires and coils, those are the only 2 things that I can find from mechanics here, a buddy at an engine builder said the same thing...even though they may be working they can be bad and not getting the proper power to fire those plugs.
Got me baffled as well. If the compression is good then it shows the valves are seating correctly, I dont know how to explain any other blow by then since the air has to bypass the valves or the piston rings to get into the crankcase as well.... so with good compression then there is no blow by as well. I will check with my cousin ( whenever I can get a hold of him as he is always busy ) and ask him, he has been a mechanic forever ( started out working funny cars and dragsters ) so he has like 40-50 years experience under his belt, so as soon as I can get in touch with him Ill post it to you. Only thing I can think of is metal expands when it gets hot... did you do the compression check on a warm motor or cold?