Broke in the 340 a few weeks ago, all went well. It's still in the run stand so I decided to check the cranking pressure yesterday. Using a screw in type compression gauge, the right bank are all 155psi, the left bank are between 137psi and 149psi. The engine was cold when I did the check. I rechecked my ring gap numbers and they're all about the same. I'm thinking maybe a valve issue, both heads were done at the same shop. Does this look like a problem or am I sweating over nothing? What would be an acceptable cranking pressure?