Product Description
Genuine 40259 Fuel Pump (Vintage Rebuilt)
Restore the fuel delivery system of your high-performance classic Oldsmobile to factory-original standards with this professionally rebuilt mechanical fuel pump. Proudly Made in the USA, this genuine vintage unit is a period-correct component essential for high-quality restorations. By utilizing high-quality original castings, this rebuilt pump maintains the authentic look and rugged durability that modern mass-market replacements often fail to provide, ensuring your Big Block V8 receives steady, reliable fuel pressure.
This specific model, 40259, is the verified fitment for 1965–1966 Oldsmobile applications equipped with the 400 and 425 cubic inch V8 engines. It is specifically designed for vehicles produced without air conditioning. This unit serves as the primary replacement for original equipment part number 644 0259 and interchanges with Carter model M4509S. It is engineered to meet the high-volume fuel requirements of Oldsmobile’s premium performance powerplants found in the 442 and Toronado during the mid-60s.
Note on Stock Photos: Due to our volume of identical, interchangeable inventory, we use representative stock photos for this model. The image is for reference only and may depict a specific manufacturer (e.g., 'AC'). You will receive a pump that meets all listed specifications, which may be from the manufacturer shown or a fully equivalent alternative.
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 pumps 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.
Key Features:
- Part Number: 40259 (Master 40259M)
- Interchange / Replaces OEM: 644 0259, Carter M4509S
- Position: Engine Mounted
- Engine Fitment: Oldsmobile Big Block V8 (400, 425 CID)
- Origin: Made in USA (Vintage Stock)
- Condition: Vintage Rebuilt
Verified Vehicle Fitment:
| Make | Model / Series | Year | Engine | Notes |
| Oldsmobile | 442 | 1965-1966 | 400 V8 | Without Air Conditioning |
| Oldsmobile | Toronado, Starfire, 88, 98 | 1965-1966 | 425 V8 | Without Air Conditioning |
Fits Years:
1965 1966
Unbeatable Prices & Expectations
We scour the country to find the best deals on NOS and NORS parts so we can pass the savings on to you. Our vintage inventory is acquired from old auto parts stores, warehouses, and private collections. While these parts are unused or professionally rebuilt, their packaging and surfaces may show signs of shelf wear or age due to decades of storage. Rest assured, every part is a genuine piece of automotive history, built to the standards of the era it represents.
