Perfect Circle MS829H20 H-Series Performance Main Bearing Set .020 Undersize

The Perfect Circle MS829H20 is a high-performance crankshaft main bearing set designed for Chevrolet big block engines including 366, 396, 402, 427, 454, and 502 cubic inch variants. This H-Series bearing set features .020 inch undersize dimensions for use with reground crankshafts, making it ideal for engine rebuilds and performance applications.

Key Features:

• Tri-metal TM-77 construction with copper-lead alloy layer, precision steel back, and electroplated babbitt surface overlay
• Medium level of eccentricity with high crush factor for superior bearing retention
• Hardened steel backing without flash plating ensures better seating and dimensional accuracy
• Enlarged chamfers provide greater crankshaft fillet clearance for performance applications
• Half-groove (180 degree) design on upper bearing for optimized oil distribution
• Developed primarily for NASCAR racing but suitable for all types of competition engines
• Ideal for engines running at medium to high RPM ranges
• Made in the USA

This set includes five main bearings (four pairs plus thrust bearing set). The H-Series bearings are engineered to reduce drag, increase horsepower, and provide reliable protection in demanding performance and racing applications. Compatible with crankshafts that have oversize fillets and medium duty truck applications.