J MARTTIN AUTO bundle set of (8) Hypereutectic pistons & MOLY Ring set compatible replacements for 1999-2003 GM family passenger car models with the 325ci 5.3L VORTEC-series V-8 VIN "T" engines. Please CHECK VIN - These VIN code "T" cars & Trucks. VIN refers to the 8th character in the vehicles ID in lower dash reading from left to right. Pistons Feature: Fully Coated 3.050 inch diameter, 0.068 inch deep recessed piston head. Press fit pins. . Cylinder Diameter: 3.780 @ STD Ring Top Landings TOP LAND: 1.50mm 2ND LAND: 1.50mm 3RD LAND: 3.00mm (oil ring). Compression Height 1.325" Pin Diameter: .9451" IMPORTANT: THESE PISTONS ARE 1999-2003 AND HAVE A .9451" PIN DIAMETER. PLEASE CONFIRM YOUR PIN DIAMETER!! 2004 AND UP USED A .9429" PIN DIAMETER.