One new -old-stock GM fuel pump-sending unit cam ring, GM part number 25124032 (TR11).  This stamped metal ring (3-7/8" OD by 3" ID; 1/8" thick) locks the fuel pump assembly to the tank on a wide variety of GM trucks (1988-2000), SUVs, and cars (1985-1999), including the classic 1988-98 GMT400 trucks.  These are often corroded and/or damaged when the fuel pump assembly is serviced.  Shipping is free to contiguous U.S. locations, and I only ship to U.S. addresses.  Please ask any questions and take a look at my other items.