Running what is basically stock 67 440 HP set up. Pistons are flat tops that are .060 in the hole, haven't cc'd the heads but they should be in the neighborhood of 79 cc's. With the stock stroke, bore and .020 head gaskets, Summits compression calculator says 10.04-1. I built another engine with the exact same short block specs, only with open chamber heads and it calculates to 9.23-1. I'm running a Summit 6401 cam, 224/234 degrees @.050, .466/.488 lift with 114 degree lobe separation, Eddy RPM intake and Hooker 1 7/8 headers and this engine makes tons of torque with great street manners. Pump gas friendly. Maybe I need to save my pennies and get some 440 Source aluminum heads for this new engine.