90-2121 Valve seat. Exhaust. 1.750" +.010"
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Specifications
- Brand
- S&S
- Part Number
- 90-2121
- OEM Reference
- 1810-79
- Pack Quantity
- Sold as ea
- Category
- Valve Seats
- VAT Rate
- 20%
About This Product
Overhauling the cylinder heads on a Shovelhead often requires replacing worn-out valve seats. This S&S exhaust valve seat is designed for 1966 to 1984 Big Twin models and is an oversized replacement for OEM 1810-79 and 18055-66B. It features a 1.750-inch outer diameter with a +.010-inch oversize dimension, making it perfect for heads where the original seat pocket has been enlarged or damaged. S&S manufactures these seats from high-quality materials to withstand the extreme heat of the exhaust port while providing a stable surface for the valve to seal against. It is an essential component for any professional head rebuild, ensuring proper valve geometry and long-term durability for your Shovelhead.
Manufacturer part number: 90-2121.
Fitment
55 models66-84 Big Twin
Electra Glide 14 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1978 | Electra Glide FLH 80 FLH-80 |
| Harley-Davidson | 1975–1980 | Electra Glide FLH-1200 |
| Harley-Davidson | 1979–1980 | Electra Glide FLH-80 |
| Harley-Davidson | 1975 | Electra Glide FLHF |
| Harley-Davidson | 1977 | Electra Glide FLHS-1200 |
| Harley-Davidson | 1980 | Electra Glide FLHS-80 |
| Harley-Davidson | 1984 | FLH Police 80 FLH |
| Harley-Davidson | 1979–1980 | Glide Classic FLHC-80 |
| Harley-Davidson | 1983 | Police FLH |
| Harley-Davidson | 1979–1980 | Police FLH-1200 FLH-1200 |
| Harley-Davidson | 1979 | Touring Electra Glide Classic FLHC-80 |
| Harley-Davidson | 1978–1980 | Touring Electra Glide FLH-80 |
| Harley-Davidson | 1977 | Touring Electra Glide Sport FLHS-1200 |
| Harley-Davidson | 1980 | Touring Electra Glide Sport FLHS-80 |
FXR 4 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1982–1984 | FXR Low Glide FXRS |
| Harley-Davidson | 1982–1983 | FXR Super Glide FXR |
| Harley-Davidson | 1984 | FXR Touring FXRDG |
| Harley-Davidson | 1983–1984 | FXR Touring FXRT |
Low Rider 2 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1977–1979 | FX Super Glide FXS-1200 |
| Harley-Davidson | 1979–1980 | FX Super Glide FXS-80 |
Police 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1975 | Glide Police FL |
Police Electra Glide 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1979–1980 | Police FLH 80 FLHP-80 |
Softail 8 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1983 | Dyna Glide Glide Custom FXDG |
| Harley-Davidson | 1983–1984 | FX Low Rider FXSB |
| Harley-Davidson | 1981 | FX Super Glide Fat Bob FXEF |
| Harley-Davidson | 1981–1984 | FX Super Glide FXE |
| Harley-Davidson | 1981–1982 | FX Super Glide FXS |
| Harley-Davidson | 1981–1984 | FX Wide Glide FXWG |
| Harley-Davidson | 1984 | Softail Standard FXST |
| Harley-Davidson | 1981–1982 | Super Glide B80 FXB |
Super Glide 4 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1979–1980 | FX Super Glide Fat Bob FXEF-1200 |
| Harley-Davidson | 1979–1980 | FX Super Glide Fat Bob FXEF-80 |
| Harley-Davidson | 1976–1979 | FX Super Glide FXE-1200 |
| Harley-Davidson | 1976–1978 | Super Glide 1200 FX-1200 |
Tour Glide 3 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1979–1980 | Tour Glide FLT |
| Harley-Davidson | 1980 | Touring Tour Glide FLT |
| Harley-Davidson | 1983 | Touring Tour Glide FLTD |
Touring 17 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1971–1973 | Electra Glide FL-1200 |
| Harley-Davidson | 1966–1968 | Electra Glide FLB-1200 |
| Harley-Davidson | 1967–1969 | Electra Glide FLFB-1200 |
| Harley-Davidson | 1981–1983 | Electra Glide FLH |
| Harley-Davidson | 1970–1974 | Electra Glide FLH-1200 |
| Harley-Davidson | 1983–1984 | Electra Glide FLHT |
| Harley-Davidson | 1983–1984 | Glide Classic FLHT |
| Harley-Davidson | 1981 | Glide Classic FLTC |
| Harley-Davidson | 1971–1975 | Super Glide FX-1200 |
| Harley-Davidson | 1974 | Super Glide FXE-1200 |
| Harley-Davidson | 1982–1984 | Tour Glide Classic FLT |
| Harley-Davidson | 1981–1984 | Tour Glide FLT |
| Harley-Davidson | 1983–1984 | Touring Electra Glide Classic FLHTC |
| Harley-Davidson | 1984 | Touring Electra Glide FLH |
| Harley-Davidson | 1983 | Touring Electra Glide Standard FLHT |
| Harley-Davidson | 1980–1984 | Touring Tour Glide Classic FLTC |
| Harley-Davidson | 1981–1983 | Touring Tour Glide FLT |
74CI (1200CC) OHV Twin 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1978 | Electra Glide FLH |
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