Join the club man, I'm in the mix of fixing my car with the same symptom. It started subtle on day, felt like the car was lobing like it was cammed up or something, by that night I noticed smoke coming from around the hood, took a look and oil was blown everywhere from my valve cover breather filter. I had 170psi on all except for 70psi from cylinder 1. After paying em nearly $400 just to rip it apart to see what was wrong with it, it turns out it was a crushed piston ring land (the groove where the piston ring sits inside the piston). So I'll put my money on thats the problem. Actually its easy to eliminate valves as a possible cause, just put some oil into cylinder 3, if the compression raises (temporarly), then its the piston (or rings), not the valves. Hopefully your cylinder wall isnt damaged, mine was lightly scratched but can just be honed out. If your gonna upgrade the pistons (mine as well while its ripped apart)remember HRC (JE) pistons are require you to bore .020 over stock. Today Im calling JE and 2 other places that make custom pistons to see about making them to my car's specs/current measurements. (its cheaper than having your block bored unless you do all the labor work yourself) Well hope this helps, anymore info I find out Ill let you know if ya need it, goodluck...