Enginetech BC303J.030 0.030 Undersize Main Bearing Set for 1961-1978 Ford Mercury 5.8L-7.0L V8 - Complete OEM-Spec Main Bearing Set
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Enginetech BC303J.010 is a 0.010 undersize main bearing set for 1961-1978 Ford, Mercury 5.8L-7.0L 351-428ci V8 engines.
Important Notes:
| Part Number | BC303J.010 |
| Bearing Size | 0.010 Undersize |
| Quantity Per Set | 5 main bearings per set |
| Engine | 5.8L-7.0L 351-428ci V8 |
| Year Range | 1961-1978 |
| Makes | Ford, Mercury |
| Country of Origin | IL |
| Weight | 1.5 lbs |
| UPC | 707473000000 |
| OEM Cross-Refs | ACL:5M685P, ACL:5M863P, FEL-PRO:4261M, King Engine Bearings:MB559AM, MAHLE:MS-685P |
Complete main bearing set covering all main journals for the V8 application - one set required per engine.
Fitment:
Enginetech main bearings are engineered to OEM specifications, drawing on over 40 years of engine rebuilding expertise to deliver the precise clearance, crush, and eccentricity required for long-term durability under both stock and moderate-performance loads. Each set is application-specific: materials, wall thickness, oil clearance, and surface finish are all matched to the crankshaft main journal geometry and operating loads of the engine family it serves. Main bearings are a wear component and must be selected to match the crankshaft main journal size - bearings sized for standard journals will not seat correctly on undersize-machined journals and vice versa, so verify your journal measurement with a precision micrometer before ordering or installing. Always replace main bearings as a complete set. Mixing new bearings with used bearings produces uneven oil clearance across the crankshaft and accelerates wear on the freshly installed bearings - the small cost of a complete set is insurance against premature failure on the bearings you just paid to install. Enginetech documents every set with clear application-specific notes, journal-size designation, and cross-references so the right part lands on the bench the first time.
WARNING: This product can expose you to chemicals including lead and nickel, which are known to the State of California to cause cancer, birth defects, or other reproductive harm.