The Comp 260H will put peak torque at about 3000 rpm and hp at about 4500 rpm but the increase over stock is through the whole range from idle up. Federal Mogul or Silvolite hypereutetic pistons are suggested. The Silvolite site has many listed for the 240/300...or at least did at one time. Your compression goal might be easier met with head and block milling...check with an automotive machinist on that. Unless you plan on considerable tinkering to get the Holley dialed in, an Edelbrock 500 cfm might be the better option.