These are the stock-replacement cylinder head bolts that are torque-to-yield and are built to the same specs as GM # 12498545. 

 They are the Gen-3 design that use three different bolt lengths and were used by GM from 1997 through mid-year 2004.

Be sure to note which head bolts you need as GM used two different style LS head bolts

 1997-2003 heads used QTY 8 155mm Bolts, QTY 2 100mm bolts, and QTY 5 45mm bolts

2004-2014 heads used QTY 10 100mm bolts, and QTY 5 45mm bolts

Includes bolts for 2 cylinder heads. 

These cannot be reused after being torqued down because they stretch when torqued.