S&S, steel breather valve. STD

High quality steel breather valve for use as stock or high performance replacement.

Note: S&S breather valves come with elongated breather holes to increase the duration of the vacuum, allowing more oil to be drawn from the cylinder heads. This has no disadvantage in any model year, either stock or Big Inch motor.
Note: that steel breathers require steel breather valve spacers. Plastic breathers require plastic spacers. Do not intermix steel and plastic parts.
Note: A .030" oversize breather is available to save worn or damaged crankcases as 970601. A JIMS breather hole reamer (MCS 978343) will ream the damaged hole to +.030" so a +.030" breather can be used.