Yes - 9:1 pistons for racing, so Dyane motors were always favourite before the right parts became more easily available to rebuild a 2CV engine to the higher spec.
2CV 602 - CR=8.5:1 (29bhp)
Dyane/Ami8 602 - CR=9:1, with assisted induction from the fan via the tube on the top of the shroud (33/35bhp, depending what you're reading)
Sparrow 720 - block machined to accept larger steel barrels, so CR may be slightly higher; 48bhp running the standard twin-choke carb and cone filter, will be a few more with assisted induction through the Visa 652 Solex. We'll know more when it's been tested on the rolling road.