Product Description
Genuine Michigan 831P Standard (STD) Crankshaft Main Bearings (NORS)
Rebuild the core of your first-generation classic GM V8 with this exceptional New Old Replacement Stock (NORS) Michigan 831P crankshaft main bearing set. Produced in the USA by the Detroit Aluminum and Brass Corporation, this vintage kit is a 100% complete, 5-journal full engine set in Standard Size (STD).This kit contains all 5 factory-matched individual component pairs required to fully service a 5-main-bearing block casting, including the flanged thrust main and specialized rear main shells.
Key Features:
- Brand: Michigan Engine Bearings (Detroit Aluminum and Brass Corp.)
- Part Number: 831P
- Position: Crankshaft Main Bearings (Full Engine Set)
- Size: Standard Size (STD)
- Factory Set Component Breakdown:
- 3x Pairs Part No. 6656CAP (Positional Mains)
- 1x Pair Part No. 6657CAP (Flanged Thrust Main)
- 1x Pair Part No. 6659CAP (Rear Main)
- Major Industry Interchanges: Federal Mogul 931M / Clevite MS-1770P / Sealed Power 931M
- Origin: Made in USA
- Condition: NORS (New Old Replacement Stock)
Fitment:
| Make / Application | Model Lineup | Year | Engine Displacement | Fitment Notes |
|---|---|---|---|---|
| Pontiac Passenger Cars | Chieftain / Star Chief / Safari Wagon | 1955 | 287 CID V8 (Gas) | Standard Size (STD); Complete 5-Main Set for Pontiac's first-year OHV V8 |
| GMC Light & Medium Trucks | 100 / 150 / 250 / 300 / 350 Series Pickups & Fenders | 1955 | 288 CID V8 (Gas) | Standard Size (STD); Fits Pontiac-built 287/288 V8 truck engine options |
Fits Years:
1955
Listing Note regarding Handwritten Box Text: The vintage handwriting on the box cover lists numbers "937M" and "527". Please note these are historical workshop inventory markers or cross-references added by a mechanic. The factory printed labeling certifies this as the standard 831P kit matching the Federal Mogul 931M application standard exclusively for the 1955 engine block casting. Intended strictly for original-specification standard size crankshaft journals.
The Fine Print
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 our fitment data using vintage manufacturer catalogs to provide you with the most accurate information possible. However, because we are human and these decades-old resources can occasionally contain errors, we cannot guarantee 100% accuracy. We strongly encourage you to perform your own due diligence and verify this part number for your specific application before purchasing. Please note that this part may also fit other vehicles or years not explicitly listed in our research.
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.
