Front Main Cap - BBM 383-440 2-Bolt

The PRO-GRAM ENGINEERING Front Main Cap BBM 383-440 2-Bolt is a precision billet steel engine block component engineered for Mopar B and RB-series small and big block applications. This front main cap secures the crankshaft's forward bearing journal with a robust two-bolt fastening design, delivering the structural integrity and concentricity required for high-performance and stock rebuild scenarios where OEM-quality fitment and durability are non-negotiable.

Manufactured from billet steel rather than cast iron, this main cap resists distortion under load and thermal cycling—critical for engines subjected to prolonged high RPM operation or aggressive fuel mapping. The 2-bolt configuration matches original Mopar specifications for the 383 and 440 cubic inch displacement platforms, ensuring proper oil gallery alignment and crankshaft support without modification to existing block hardware. Weighing 2.6 lbs, the cap integrates seamlessly into complete engine assembly workflows and maintains factory tolerances essential for crankshaft runout and bearing clearance specifications.

Restoration shops, vintage muscle car builders, and performance engine machinists rely on precision main caps when rebuilding or upgrading classic Mopar big blocks. The front main cap position bears higher stress during combustion cycles and engine braking events, making material quality and manufacturing precision direct investments in long-term reliability. This PRO-GRAM ENGINEERING component satisfies OEM interchange requirements and is suitable for street, strip, and show applications where Mopar B/RB authenticity and structural durability are expected standards.