That will depend on the cam really and the setup, i.e. manifold type, runner length etc and if it's just a bolt on or something which has mappable ignition for example.
I don't know what 'cup cams' are but we gained 19bhp using a 264deg cam on standard compression and a nice mid range. Within the next few weeks we should see what the car makes with a compression hike. Although this will only be a guide as we use 48mm taper bore Jenvey throttlebodies and we run on a dyno dymanics rolling road, so figures should only be taken on a comparative basis and not as literal figures.