Why are 318's low HP and torque?

I know the early LA 318's had good compression, 9.5 to 1, if im remembering right, but they got changed in the mid seventies (74?) to 9 to 1, then in 76 or 77 they were changed to 8 to 1, unfortunately, those 8 to 1 motors were the main motor for most mopars at the time, and therefore, the most common, so its not the 318 that was a bad motor, its just the numbers of gas crisis motors that skew the results. :wack: