Cometic, cylinder base gasket. Rear. .031" fiber - 63-65 Panhead; 66-84 Shovelhead (NU) 3692 88" to 107" big bore

88" to 107" big bore conversion piston set

1-3/4" headpipe steps up to 1-7/8" into the collector to increase flow and improve performance

designed for Twin Cam ignition systems that are designed to be used with Twin Cam style low resistance coils

OEM style replacement for 74523-92A

With pre-drilled mounting holes

Cometic, cylinder base gasket. Rear. .031" fiber - 63-65 Panhead; 66-84 Shovelhead (NU) 3692 88" to 107" big boreRear gasket. . 031" fiber, a premium hi temperature, hi density creep resistant material that requires no re torquing, no additional sealants, is fuel resistant and asbestos free. OEM replacement reference 16777 63.