440 Source forged pistons are American-made and available in a number of compression ratios. We specified pistons with a 17cc dish to yield a 9.85:1 compression ratio with the 90cc combustion chambers in our 452-casting Chrysler cylinder heads and 0.039-inch-thick Fel-Pro composite head gaskets. The new pistons weigh 758.4 grams each (with pins). By comparison, a stock Chrysler cast-aluminum, flat-top 440 piston weighs a hefty 1,027.6 grams. Any reduction in reciprocating mass pays dividends by reducing stress, enhancing throttle response, and boosting mechanical efficiency.