Jeep Strokers

Hi
My Jeep Stroker has mounted a 0630 head. I have mesasured the volume of the combustion chamber is about 58 cc.
What is the theorical volume?

That sounds right. I've measured the chamber volume at 56.5cc on my old 4.0 7120 head and 57.0cc on the 7120 head that currently sits on my stroker.

Use the 58cc volume you measured when doing your calculations. If you have the head shaved, then it will be slightly less, so re-measure.