Need more info but sounds like you need a complete rebuild. Strip the motor down to a bare block and take it to a machine shop for a .030 over bore (or what they recommend) and buy a deluxe rebuild kit from PAW. Not sure of the cost but I'm sure it you're in for over $500. As far as "real good power", not sure what that means but better flowing heads is a good place to start. Intake, carb and heads will help. Of course, a cam that is matched to your heads will help a lot.