Using sophisticated equipment such as this TR250 Tallyrond machine allows development of piston skirt profiles that hold the piston square in the bore. Maximizing skirt contact spreads the load, minimizing drag and extreme pressure points, a key issue with small-block Ford stroker engines. "Flat ring grooves are essential in making horsepower," says Naegele. Measurements taken here result in a six-decimal place (0.000001) number. That's about as accurate as it gets.