Pro Copper Head Gaskets without water holes, for Chrysler 354-392 Early Hemi. Bore Opening: 4.010″; Gasket Thickness: .050″; Material: Annealed Copper; Bolt holes: 5/8″ Dia. Fitment Notes: (1) NW suffix gaskets have no coolant passages for use in dry block alcohol or nitromethane racing engines. (2) SCE has modified the pushrod holes in all P67___NW suffix head gaskets to allow proper oil drainage for AJPE Billet 392 heads; *Pro Copper head gaskets require O-rings in the block or head*. Package Contents: 1 Pair.