Speed-Pro Competition Series Main Bearings 139M1 Bearings, Competition, 0.001 in. Crankshaft Undersize, Tri Metal, 3/4 Groove, Chevy, 302, 305, 350, Set of 5
Speed-Pro Competition Series Main Bearings 139M1 Bearings, Competition, 0.001 in. Crankshaft Undersize, Tri Metal, 3/4 Groove, Chevy, 302, 305, 350, Set of 5
Description
Main Bearing - Speed Pro - 0.001 in Undersize - Small Block Chevy - Kit
Data: v2 - Desc: v4.2 - Upd: 2026-11-08 14:27:24
Features
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Specifications
Reference Information
| Reference Data (Provide these details to our support team) | |
|---|---|
| Brand Name/s | Sealed Power |
| StreetFX SKU | slp139M1 |
| SFX Item ID | 5029087 |
| Accounting SKU | slp-139M1 |
| Manufacturer SKU | 139M1 |
| Manufacturer UPC | 724956232864 |
| Alternative References | SEA139M1, SLP-139M1 |
Main Bearings, Competition, 0.001 in. Crankshaft Undersize, Tri Metal, 3/4 Groove, Chevy, 302, 305, 350, Set of 5
If you're building a serious performance engine, then you'll want to consider Speed-Pro Competition Series main bearings. They were developed in NASCAR and Pro Stock competition, so you know they're tough. The bearings are built on premium 1020AK steel backings and overlaid with Speed-Pro's super-duty H-14 alloy. That layer is then covered with a nickel barrier, followed by a thin lead-tin-copper overplate. However, unlike other performance bearings, there is no flash tin layer on top of that. Speed-Pro's engineers have determined that such a layer can actually move around under high loads—sometimes with undesirable consequences. Depending on the application, these main bearings have oil grooves for enhanced lubrication, while maintaining a maximum bearing surface area. They also feature Speed-Pro's exclusive contoured-flange thrust bearing technology for higher thrust-loading capacity. Competition Series main bearings are available in nearly a hundred configurations for countless vehicle and engine applications.
| Product Attributes | |
|---|---|
| Brand | Sealed Power |
| Manufacturer's Part Number | 139M1 |
| Part Type | Main Bearings |
| Product Line | Speed-Pro Competition Series Main Bearings |
| UPC | 724956232864 |
| Bearing Usage | Performance |
| Engine Crankshaft Undersize (in.) | 0.001 in. |
| Engine Crankshaft Undersize (mm) | 0.025mm |
| Grooved Bearing | Yes |
| Groove Location | Upper and lower |
| Groove Style | 3/4 |
| Thrust Bearing Oversize | Stock |
| Bearing Material | Tri-metal copper-lead alloy |
| Quantity | Sold as a set of 5. |
Compatibility
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