[jluetjen]

I suspect that what you're noticing is the increased torque across the rev range. Driving my 2.0E with S pistons compared to a 2.2E with E pistons, they're actually pretty close. The peak HP number doesn't change much since that is really a function of peak air flow. Increasing the CR does help to prop up the combustion chamber pressure above the peak torque RPM, but the percentage benefit is pretty small when you look at the peak HP number, not to mention how many people can feel a few % improvement at 6500 RPM?

But the engine's performance at lower RPM's (off-cam) is much easier to sense, especially since most of us spend most of our time at those rev's. Here's one piece of data, note that I've plotted BMEP rather then HP. BMEP is not dependant on the engine size like HP is.

BMEP
RPM 70S 72S
CR> 9.8:1 8.5:1
2000 133 125
2500 133 133
3000 138 143
3500 144 151
4000 153 160
4500 162 167
5000 166 172
5500 168 171
6000 167 169
6500 164 162
7000 150 148

Note that the '70S had better performance below 2500 RPM, and above 6500 RPM. The '72S did better in between? Why? I suspect that the lower dome in the pistons improved the combustion chamber shape (always a weakness of Hemi heads) which made up for the reduction in CR. Now getting 9.8:1 in a 2.4 liter 72S doesn't require as large of a dome as in 2.2 70S because the 2.4 liter 72 has a longer stroke, which allows you get the same CR with a smaller dome. So I would expect the 2.4 with 9.8:1 to have a BMEP level more like the best of both of those columns of data.