This listing is for (8) Hypereutectic Flat Top coated Pistons with Floating pins compatible with 1999-2009 GM Chevrolet LS 4.8L & 5.3L Engines GEN III & IV in your choice of sizes. These pistons are replacements for these applications: 1999-06 4.8L VIN Code "V" and 2005-2009 4.8L VIN Code "C" or "K". Also fits, 2005-09 5.3L VIN Codes "B", "M", "J", "0", "3" & "C" engine LM4, LS4, L33, LH8, LH6, LMG, LY5. All with Floating Pins. Pistons are Hypereutectic Coated Skirts includes Pins. Compression Height: 1.323, NOTE: Pin Diameter: .943"; pins included ( Please measure for accuracy). Some early models had .945" Pin. Ring Grooves are: 2@1.5mm and 1 @ 3.0MM thickness.