160 cranking psi; advance the cam or run it?
"MY" rule of thumb using a compression gauge coupled with degreeing a cam (and I use one on all that I do) is that if I can get the cranking compression to fall off at no more than 6* advanced, I go with the compression gauge, if not, I don't. Not every combination will peak and fall off within that range. Take for instance a 508 cam in a 9:1 motor. We all know that is WAY over cammed. As such, you can probably advance that cam in that motor 10 or more degrees before cranking compression peaks and falls off. That certainly doesn't mean we run it that far advanced. Using the compression gauge is an old tuner's trick that was taught to me years ago. I was shown that you don't just keep advancing if it doesn't fall off. You have to have a feel for it for sure. The way some of this stuff is being machined nowadays <insert eyeroll here> you may have to change cam timing by 10* before you get to where the cam card says to install it and THEN start compression gauge tuning. That's the main reason I like incorporating the gauge. It just gives you another tool to degree by.