Well knowing the exact static compression is a must and knowing the cranking compression is real usefull in picking a cam that will allow the fuel you want to run. or the fuel you want to run and what cam.
I have a 272 deg @ .050 cam 10.5 to 1 static compression and it had 155 average cranking compression at install of 106 advanced the cam to 102 and it has 165 average which is still way short of what 94 pump gas will allow.
This program says 172 lbs so close as my two highs are 170 other 6 are right at 160
put 0 in for boost and it's @.050 been close on all motors I've dealt with.
http://www.rbracing-rsr.com/comprAdvHD.htmI'm in the process of bumping my compression and my target is 190 to 195 for the highs and the ring seal probably not as good on the rest so 180 will have to do till I pull motor and have it torque plated and re honed.
I think most builders now like to aim at a max cranking compression of 185 for 93 octane!!