Ok- I installed my Noss head the other day w/19 cc domes. I followed the installation process step by step. I torqued it down 5,10,15, then 20. I checked the compression, it was only reading 120psi. I should be around 170-180psi. So I thought maybe it just needed to be run for the o-rings to seal. So I started it up yesterday, it ran awesome!!! I let it warm up for 5 minutes, then I drove it around my neiborhood for another 5 minutes. It ran better than it ever has. So I pull it back into my garage and checked the compression again on both cylinders. Still, only 120 in both cylinders. What the hell?? The only things I think it could be is a faulty compression gauge (the gauge is brand new though)? Or when I installed the head I left the factory gasket on, and I also installed the o-ring too. Would that effect it? Or one of the o-rings could have came off when I was pushing the head down onto the studs. Any sugeestions? Thanks in advance, sorry for the long post!