Combustion Chamber size

I have a question for you engineers out there that I have been pondering on for some time. In a fuel engine blown or injected what is the difference the engine sees in say a 170cc chamber and a 100cc chamber on a hemi when the cc's at tdc are the same in both?

 

The piston is lighter with a small chamber. Also the flame travel is less.Actually there is very little power gained by having a smaller chamber, just look at the numbers,a Bob Newberry head which has fairly large chamber, and a Brad Anderson fathead which has a small chamber. Both perform close to the same.