Notes: Non street legal. Cast iron or aluminum head. 4.840" bore centers. Pre flattened steel wire combustion seal. Steel core laminate construction. Two coolant holes per end. Three lower coolant holes. Minimal brinelling of aluminum head.

Notes: Non street legal. Will also fit Yates cylinder head. MLS bore bead combustion seal. PermaTorque MLS multi layer steel construction. 3 active layers. 2 shim layers.

Notes: Non street legal. Cast iron or aluminum head. Pre flattened steel wire combustion seal. Steel core laminate construction. Extra large bore. Extra thick to reduce compression and correct piston valve clearance problems. Can be used on aluminum blocks with liners. Minimal brinelling of aluminum head.

Notes: Non street legal. Cast iron or aluminum head. MLS bore bead combustion seal. PermaTorque MLS multi layer steel construction. Can be used on aluminum blocks with liners. Minimal brinelling of aluminum head.

Notes: For high performance engines only. Cast iron or aluminum head. Steel core laminate. Pre flattened steel wire combustion seal. 4.190" bore. 0.041" thickness. Volume: 9.2cc. Can be used on 400 race engines. Can be used on aluminum blocks with liners. Minimal brinelling of aluminum head.

Notes: For high performance engines only. Steel core laminate. Pre flattened steel wire combustion seal. 4.166" bore. 0.041" thickness. Volume: 9.1cc. Minimal brinelling of aluminum head.

Notes: Non street legal. Cast iron or aluminum head. Loc-Wire steel wire stainless steel core laminate. Requires precision machined receiver groove in head. Can be used on aluminum blocks with liners. Severe duty.

Notes: For high performance engines only. Stainless steel core laminate. Pre flattened steel wire combustion seal. 4.250" bore. 0.039" thickness. Volume: 9.2cc. Minimal brinelling of aluminum head.

Notes: Non street legal. Cast iron or aluminum head. Pre flattened steel wire combustion seal. Stainless steel core laminate construction. Can be used on aluminum blocks with liners. Minimal brinelling of aluminum head.

Notes: Non street legal. W8 with 18 bolt heads. Pre flattened steel wire combustion seal. Steel core laminate construction. Minimal brinelling of aluminum head.