New 425 flat top pistons with approximately 3 cc valve reliefs. Much lighter and stronger than the original factory pistons. Uses 1/16x1/16x3/16 rings for less drag and more horsepower. Choose size at checkout. Includes spiral locks and wrist pins which can be floated or pressed. Can be used with factory rods (pressed) or our DMR-5455-7-FORGED-O billet steel rods (floated).