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Restore the original charging performance of your classic powertrain with this genuine Motorcraft GR-21 Voltage Regulator. This authentic New Old Stock (NOS) component, also identified by Ford engineering number C0AF-10505-B, is a critical 12-volt 3-unit mechanical regulator designed for 40-amp generator systems. Manufactured in the USA, this original equipment part provides factory-correct electrical calibration for 1956-1964 Ford passenger cars and trucks, including the F-100, Fairlane, Galaxie, Falcon, and early generator-equipped 1964-1/2 Mustang models, as well as period Mercury models like the Comet and Monterey. By using an original NOS regulator, you ensure the precise voltage control necessary to maintain your vintage battery and electrical accessories in a factory-correct restoration.
| Make | Model | Year | Engine | Notes |
|---|---|---|---|---|
| Ford | F-100 / F-250 / F-350 | 1956-1964 | V8 / I6 | 12V Generator / 40A System |
| Ford | Fairlane / Galaxie / Falcon / Custom / Thunderbird | 1956-1964 | V8 / I6 | 3-Unit Generator Regulator |
| Ford | Mustang | 1964 | V8 / I6 | 1964-1/2 Models with Generator |
| Mercury | Montclair / Monterey / Comet / Meteor | 1957-1964 | V8 / I6 | 12V Generator Models |
| Chevrolet / GMC | C10 / C20 / C30 / K10 / K20 / K30 Pickups | 1960-1964 | V8 / I6 | Delco-Equipped 35-42A Systems |
1956 1957 1958 1959 1960 1961 1962 1963 1964
Note on Stock Photos: Due to our inventory of multiple identical units for this specific part number, we utilize representative stock photos for this listing. You will receive a component that strictly meets all listed specifications and fitment requirements. Please be aware that because these are vintage parts, minor cosmetic variations—such as surface finish, color, or production markings—may exist between different manufacturing runs. These slight aesthetic differences are a result of historical production processes and do not impact the part's integrity, performance, or authenticity.
A Note on Fitment Accuracy: We manually research and cross-reference our fitment data using vintage manufacturer catalogs. While we strive for 100% accuracy, these decades-old resources—and the humans reading them—can occasionally contain errors. Additionally, these parts may fit other vehicles and years not explicitly listed in our data. To ensure a seamless restoration, we kindly ask that you perform your own due diligence and verify that this specific part number is correct for your application prior to purchase.
While many of our vintage parts were manufactured decades ago, they remain unused and high-quality. Some original boxes may show signs of shelf-wear, such as dust, tape, or surface distress from years of storage. Rest assured, the components inside have been inspected to ensure they are complete and ready to help you finish your project without breaking the bank.