Description
The S&S CYCLE 900-0251 cylinder heads deliver the port flow efficiency needed to maximize performance gains both now and through future upgrades. Whether you’re running a stock big-twin or planning forced induction modifications, these fully assembled heads provide the foundation for reliable, repeatable power across the entire RPM range. Available in 79cc and 89cc configurations, they’re engineered to match your specific displacement and compression strategy.
Key Specifications:
- Fully assembled, ready-to-install
- 79cc chamber capacity
- 1.940″ intake valve
- 1.575″ exhaust valve
- .650″ valve lift rated
- 89cc chamber option available
- 2.000″ intake (89cc)
- 1.605″ exhaust (89cc)
- .640″ spring rate (89cc)
- Fits 88″ to 103″ displacement
- 89cc for 103″+ or high-compression
- OEM rocker box compatible (79cc)
- CNC-machined construction
- Compression release provision
- Accepts OEM intake manifolds
- Four long headbolts included
- Reuses four OEM bolts
- Requires S&S Lower Rocker Box Gasket Kit (0934-4574)
- Made in the U.S.A.
- Note: S&S rocker boxes required with compression releases






