Genuine Johnson SET-723 X10 Main Bearing Set (NORS)
This is a premium NORS (New Old Replacement Stock) Main Bearing Set manufactured by Johnson. Specifically engineered for the unique air-cooled Chevrolet horizontally-opposed six-cylinder engine family, this set provides high-precision support for the 140, 145, and 164 cubic inch engines found in the Chevrolet Corvair and Corvair 95 trucks. Proudly made in the USA, these bearings are essential for maintaining proper crankshaft alignment and oil pressure in both naturally aspirated and turbocharged applications, including Monza and Corsa models. These bearings are finished to a .010" (X10) undersize, requiring the crankshaft journals to be ground to match for a professional-grade vintage engine rebuild.
Key Features:
- Brand: Johnson
- Part Number: SET-723
- Position: Crankshaft Main Bearings
- Engine Fitment: Chevrolet Flat-6 (140 / 145 / 164 CID)
- Size: .010" Undersize (X10)
- Origin: USA
- Condition: NORS (New Old Replacement Stock)
Verified Vehicle Fitment:
| Make |
Model |
Year |
Engine |
Notes |
| Chevrolet |
Corvair (All Models / Monza / Corsa) |
1960-1969 |
140 / 145 / 164 Flat-6 |
Includes Turbocharged models |
| Chevrolet Truck |
Corvair 95 / Greenbrier / Rampside |
1961-1965 |
145 / 164 Flat-6 |
Air-cooled models |
Fits Years:
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
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.
