It's already done, but, I was wondering if there is a "general rule" or way of best guessing increased HP/Torque without going to the Dyno?

I've got a 930/02 Euro Carrera 3.0 that had a piston(s) mishap... I bought the car that way and had the engine refreshed. The only change I incorporated besides refreshing the heads was to switch from the 8.5 Euro compression to some used '78 SC P/Cs at 9.3. This is a CIS engine. IF the Euro rated engine is really 200hp, did I do myself any favors by increasing compression a bit? Anybody venture a best guess about hp/torque and what it might be? Any downsides to this action? (a little late now I suppose)

thanks,