High performance head gaskets bt evo 84/99 spt 1200cc 88/l* 4.000 bore .040 c9880

4" (Big Bore) bore size, .040" thickness
Fits Big Twin Evolution 1984/1999 & Sportster Evolution 1200cc 1988/Later

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