You can get 700, 800 or 900 hp out of those heads. Just depends what parts you put around them.

Your motor sounds like maybe 750 to 800 hp with 13:1 compression and a modest cam. I didn't start to make serious power with my EZ heads until we converted them over to Jesel rocker arms. Once we had the high ratio Jesel arms and we cranked the compression up to 15:1 the engine came alive.