[Plays with cars]

Yes, you're right. Using the 2.2 pistons w/ the 2.4 stroke results in higher compression; 10.3:1 static compression for this combination.

Because of this though, dynamic compression is important to consider. It is a further refinement of the static compression number and represents the 'fixed' engine variables that determine cylinder operating pressure. Its a combination of static compression, camshaft specs/timing, and engine geometry (specifically stroke and rod length). By including these other variables it is a better representation of engine's efficiency potential and risk for detonation.

You will sometimes see very hot cam advertisements including a recommendation for higher static compression; this is to increase the dynamic compression and improve low speed performance.

I had the opposite concern where I am running high static compression and don't have a hot cam installed. I wanted to make sure I wasn't going to end up w/ too high of dynamic compression and have problems with detontation.