Exhaust Valve Guide. Fits Sportster 1957-Early 1983. Standard Outside Diameter Guide.

* Designed for Harley-Davidson heads

* Use with OEM style valve seals

* Cast Iron

* High temp viton o-ring seal

* Smooth lead-in

* CNC machined

* Guide ID unfinished - Requires honing

* OD = .5645" Std size

* ID = .339"

* Replaces OEM # 18170-57B