These forged, 4" bore flat-topped pistons are intended for use in S&S® 4" bore Super Sidewinder® engines as well as other custom 4" bore engines.
Fitment
| Year(s) | Make | Model Code | Model |
|---|---|---|---|
| 1984-1999 | Harley-Davidson | — | Big Twin |
| 1986-2003 | Harley-Davidson | — | xl |
