Set (8) .020 over size 3.800 bore diameter hypereutectic, coated dish top pistons and a moly piston ring set compatible with 2004-2007 Chevrolet GM Trucks using the 5.3L Vortec V-8 LM7, L59, LM4 engines requiring floating piston pins and with Vin Codes P, T or Z. Vin refers to the 8th character in the vehicles ID in lower driver side dash from left to right. P/N (8) DAC1091 Kit 20. These replacement pistons and rings are manufactured to meet or exceed O.E.M. specifications. Compression distance: 1.323, Pin diameter: .943, Rings widths:1.5mm,1.5mm & 3.0 mm.