This listing is for a set of (8) Speed Pro Hyper-eutectic flat top 4 valve relief pistons & matching moly rings set compatible replacements for Dodge Plymouth 360 engines. Available in your choice of sizes needed. Pistons are Not Factory, OE duplicate pistons! Use as a performance upgrade only. Good for street/strip or light race. 5/64" 5/64" 3/16" ring grooves. Pin diameter: .984" (included). Stock length rods. Press-fit only. Stock 3.578" stroke.