This listing is for a set of (8) +.030" over size 3.810" Bore diameter 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.VIN refers to the 8th character in the vehicles ID in lower dash reading from left to right. This listing is for eight (8) dished pistons and a matching Hastings or NPR Ring set depending on availability at time of purchase. Coated skirt 3.050 inch diameter, 0.068 inch deep recessed piston head. - CHECK VIN - THESE FIT VIN "T" CARS AND TRUCKS - PRESS FIT PINS. CYLINDER DIAMETER: 3.800" (at +.020") TOP LAND: 1.50mm 2ND LAND: 1.50mm 3RD LAND: 3.00mm (oil ring). COMPRESSION HEIGHT 1.325" PIN DIAM. .9451" DISH PISTON: .068" DEEP X 3.05" ACROSS. 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.