The laminated Xoar is the better prop. Most of that extra rpm found with the Beech prop is lost through inefficiency. You'll have higer rpm numbers with the Beech, but lower actual performance.

Regarding Dick Pettit's method of using a Permatex gasket sealer. Anything that oozes to the outside also oozes to the inside. Anything that oozed to the inside became a port restriction after it dried, reducing the engine's ability to exhaust hot gasses. Not a very smart thing to do.