1997-2003 LS9 Head Gaskets and Bolt Kit Kit Includes: LS9 Head Gaskets (best gasket to use on most LS builds) 2 sets of early style Head Bolts (8 long and 2 short bolts per head) Prior to 2004, all of the Gen3 and Gen4 GM small block engines had head bolts of varying lengths. In early 2004, GM changed the head bolt design from that style to the new style which are all the shorter length. Please be sure you know which style bolts your vehicle requires before ordering. LS9 Performance Multilayer Head Gasket for LS9 engines, can also be used with 5.3, 5.7 6.0 6.2 blocks. 4.100" bore, .055" compressed thickness, 7 layer These are know as best gaskets for engines up to 4.100" bore. Very common head gasket to use on Turbo and Supercharged engines.