Perfect Circle MS1277HG H-Series Main Bearing Set Chrysler 440 V8 Standard Size

The Perfect Circle MS1277HG is a high-performance H-Series main bearing set engineered for Chrysler 440 cubic inch (7.2L) V8 engines from 1974-1979. This set includes five full-groove bearings designed specifically for blocks with the larger 3.870"/3.930" main bearing flange outside diameter found in 1974 and later RB engines.

Key Features:

• Tri-metal construction with hardened steel backing for maximum strength and durability
• Medium level of eccentricity with high crush factor for optimal seating and oil retention
• Made without flash plating to improve bearing seating characteristics
• Full-groove oil distribution design ensures proper crankshaft lubrication
• Enlarged chamfers at bearing edges provide clearance for oversize crankshaft fillets
• Standard bore: 2.9425"-2.9430" with 0.095" maximum wall thickness
• Standard journal size: 2.750" for stock crankshafts

Performance Engineering:

Originally developed for NASCAR racing applications, Clevite H-Series bearings excel in medium-to-high RPM engine builds. The tri-metal construction features a steel backing bonded to a copper-lead intermediate layer, topped with a carefully selected thin overlay that provides excellent conformability and embeddability. These bearings are ideal for performance street engines, mild racing applications, and engine rebuilds where durability and longevity are priorities.

Important Compatibility Note:

This bearing set is specifically designed for 1974-1979 Chrysler RB 440 engines with the large thrust configuration. It will not fit 1973 and earlier 440 engines which use different thrust dimensions. The full-groove design ensures maximum oil distribution while maintaining adequate load-bearing surface area.

Clevite has been a trusted name in engine bearings since 1948, with proven performance in everything from daily drivers to race engines producing thousands of horsepower. Each bearing set is manufactured to exacting tolerances to ensure proper clearances and optimal engine performance.