• 3 1/2" (standard) bore size, .040" thickness
• 3 Piece Design
• Extreme Sealing Technology (EST) will eliminate head gasket problems
• These are the best that we have ever seen for everything from 8.5:1 compression ratio up to 15:1 plus
• Three piece design features an aluminized stainless steel center sandwiched between two NBR coated stainless spring steel outer layers
• To ensure the utmost sealing power, the outer layers are embossed at the cylinder bore and the oil drain backs provide a seal so good that O rings are not required
• Distributes heat exceptionally well from the head to the cylinder, thus eliminating hot spots that would normally cause a head gasket failure

Fits:

• 1984-1999 Harley-Davidson Big Twin Evolution
• 1988-Later Harley-Davidson Sportster Evolution