Product Description
Genuine Federal Mogul 4945M-20 Main Bearing Set (NORS)
This genuine Federal Mogul 4945M-20 Main Bearing Set is a premium New Old Replacement Stock (NORS) component, specifically engineered for the 140 cubic inch (2.3L) aluminum block L4 engine used across several GM divisions. Manufactured in the USA, these bearings provide the essential oil clearance and high-load durability required for 1975-1977 Chevrolet Vega and Monza, Oldsmobile Starfire, and Pontiac Astre and Sunbird models. Featuring a .020" undersize, this set is a critical requirement for maintaining proper crankshaft alignment and restoring correct oil pressure in engines where the crankshaft journals have been professionally turned. It is a direct fit for the final generation of GM's H-body overhead cam four-cylinder power plants.
Key Features:
- Brand: Federal Mogul
- Part Number: 4945M-20
- Position: Crankshaft Main Bearings
- Size: .020" Undersize
- Engine Fitment: 140ci L4 (2.3L OHC)
- Origin: Made in the USA
- Condition: NORS (New Old Replacement Stock)
Verified Vehicle Fitment:
| Make | Model | Year | Engine | Notes |
|---|---|---|---|---|
| Chevrolet | Vega / Monza / Panel Express | 1975-1977 | 140 L4 (2.3L) | Aluminum Block OHC |
| Oldsmobile | Starfire | 1975-1977 | 140 L4 (2.3L) | Aluminum Block OHC |
| Pontiac | Astre / Sunbird | 1975-1977 | 140 L4 (2.3L) | Aluminum Block OHC |
Fits Years:
1975 1976 1977
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.
Unbeatable Prices & Expectations
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.
