King Engine Bearings MB1328XP STDX pMax Black Race Main Bearing Set GM Vortec LS-Series Gen III/IV

The King Engine Bearings MB1328XP STDX is a standard size trimetal race main bearing set engineered for GM Vortec and LS-Series Generation III and IV engines. Featuring King's exclusive pMax Black coating technology, these bearings are purpose-built for high-performance and racing applications where stock bearings simply can't keep up.

pMax Black Coating Technology:

• Advanced polymer-based black overlay dramatically reduces friction and wear during cold starts and high-RPM operation
• Superior conformability allows the bearing to adapt to minor surface irregularities in the crank journal
• Excellent embeddability — small debris particles embed into the overlay rather than scoring the crankshaft
• Enhanced corrosion resistance compared to standard bearing overlays

Trimetal Construction:

• Three-layer design: steel backing, copper-lead or aluminum alloy intermediate layer, and the pMax Black polymer overlay
• Higher load capacity than bimetal bearings — ideal for forced induction, nitrous, and high-horsepower builds
• Tight, consistent tolerances for optimal oil film retention and bearing crush

Key Features:

• Part Number: MB1328XP STDX
• Size: Standard (STDX)
• Application: GM Vortec and LS-Series Gen III/IV engines
• Bearing Type: Race-grade trimetal main bearing set
• Overlay: pMax Black polymer coating
• Quantity: Full main bearing set

King Engine Bearings is a globally recognized manufacturer trusted by professional engine builders and motorsport teams worldwide. The MB1328XP STDX delivers the precision fitment and durability required for both street/strip and dedicated race engine builds on popular GM LS-platform engines.