504521 Replacement 7:1cr 1340cc Shovel cast piston. +.040"
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Specifications
- Brand
- MCS
- Part Number
- 504521
- OEM Reference
- 504521
- Pack Quantity
- Each
- Category
- Pistons
- VAT Rate
- 20%
About This Product
This +0.040-inch oversize replacement cast piston with a low 7:1 compression ratio is designed for late 1978-1984 1340cc Shovelhead engines that need a larger overbore while maintaining reduced compression for improved reliability. The lower compression ratio reduces engine stress, running temperatures, and mechanical loading, extending overall engine life. Each piston includes wristpin and clips, with rings available separately. Cast type construction provides stable dimensions and an economical price point. A practical choice for high-mileage Shovelheads where both cylinder wear and reduced stress operation are priorities. Professional installation and standard break-in procedures are required for optimal results.
Manufacturer part number: 504521.
Fitment
46 modelsL78-84 1340cc Shovel
Electra Glide 12 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1978 | Electra Glide FLH 80 FLH-80 |
| Harley-Davidson | 1979–1980 | Electra Glide FLH-80 |
| Harley-Davidson | 1980 | Electra Glide FLHS-80 |
| Harley-Davidson | 1984 | FLH Police 80 FLH |
| Harley-Davidson | 1979–1980 | Glide Classic FLHC-80 |
| Harley-Davidson | 1982 | Police Electra Glide FLH-1200 |
| Harley-Davidson | 1982–1984 | Police Electra Glide FLH-80 |
| Harley-Davidson | 1980 | Touring Electra Glide Classic FHL-80 |
| Harley-Davidson | 1979 | Touring Electra Glide Classic FLHC-80 |
| Harley-Davidson | 1980 | Touring Electra Glide FL-80 |
| Harley-Davidson | 1978–1984 | Touring Electra Glide FLH-80 |
| Harley-Davidson | 1980 | Touring Electra Glide Sport FLHS-80 |
FXR 3 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1982–1984 | FXR Low Glide FXRS |
| Harley-Davidson | 1982–1983 | FXR Super Glide FXR |
| Harley-Davidson | 1983–1984 | FXR Touring FXRT |
FXR Police 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1984 | Police Low Rider FXRP |
Low Rider 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1980 | FX Super Glide FXS-80 |
Police Electra Glide 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1979 | Police FLH 80 FLHP-80 |
Softail 7 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 | FX Super Glide FXS |
| Harley-Davidson | 1981–1983 | FX Wide Glide FXWG |
| Harley-Davidson | 1981–1982 | Super Glide B80 FXB |
Super Glide 3 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1979–1980 | FX Super Glide Fat Bob FXEF-80 |
| Harley-Davidson | 1983–1984 | FX Super Glide FXS-80 |
| Harley-Davidson | 1980 | Super Glide B80 FXB-80 |
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 13 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1982–1983 | Electra Glide FLH |
| Harley-Davidson | 1983–1984 | Electra Glide FLHT |
| Harley-Davidson | 1981 | Glide Classic FLHC |
| Harley-Davidson | 1984 | Glide Classic FLHT |
| Harley-Davidson | 1982–1983 | Tour Glide Classic FLT |
| Harley-Davidson | 1981–1984 | Tour Glide FLT |
| Harley-Davidson | 1981–1982 | Touring Electra Glide Classic FLHC |
| Harley-Davidson | 1983–1984 | Touring Electra Glide Classic FLHTC |
| Harley-Davidson | 1984 | Touring Electra Glide FLH |
| Harley-Davidson | 1982–1984 | Touring Electra Glide Sport FLHS |
| 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 |
Wide Glide 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1980 | FX Wide Glide FXWG-80 |
74CI (1200CC) OHV Twin 1 model
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 1978 | Electra Glide FLH |
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