A good healthy Commander will have right at 140 psi WITH the high compression cylinder head. The early Commanders did not have the upgraded head, and will be a little lower than 140.. Chris Craft came out with the high compression head upgrade, so you could soup up your motor. Be careful with your ignition points, if you break them, their hard to come by. Wait till you run that motor….you’l love it! Man they are screamers.
Ask Lee Holland about the casting #s on the cylinder heads, as I can’t remember the #’s off hand with regards to identifying them. I would have to drop the cowl jackets on mine and look to see. let me know if you need more info.