Speedmaster Chevy SBC 350 OEM 2-Bolt to 4-Bolt Splayed Billet Steel Main Caps (Middle 3)

The Speedmaster PCE289.1002 is a set of three billet steel main caps designed to upgrade Chevy small-block 350 (SBC) engines from OEM 2-bolt to stronger 4-bolt configurations. These splayed-style main caps are precision-machined from billet steel for superior strength and durability, supporting high-performance builds and increased engine stress. The caps fit the middle three positions of the SBC 350 block and are engineered to work with 4-bolt applications, making them ideal for street performance, rebuilt engines, and racing applications where main cap reinforcement is critical.

These billet steel caps replace the stock 2-bolt main caps and are machined to OEM-compatible specifications. The upgrade provides better clamping force distribution and reduced block flex during high-RPM operation, which is essential for engine reliability in boost, nitrous, or high-output naturally aspirated builds. Speedmaster's precision engineering ensures proper fitment and alignment with your existing SBC 350 block and crankshaft assembly.

Key Features & Benefits

• Billet Steel Construction: Precision-machined from billet steel for maximum strength and durability.
• 2-Bolt to 4-Bolt Upgrade: Converts OEM 2-bolt main cap configuration to stronger 4-bolt design.
• Splayed Cap Style: Splayed geometry improves clamping force and reduces block flex during high-RPM operation.
• SBC 350 Specific: Engineered for Chevy small-block 350 engines with proper OEM compatibility.
• Middle 3 Caps Included: Set contains the three middle main caps required for the conversion.

Specifications

Ideal Applications

• High-performance and racing engine builds requiring main cap reinforcement
• Rebuilt SBC 350 engines designed for increased horsepower and boost applications
• Street performance builds where engine reliability under stress is critical
• Nitrous oxide or supercharger-equipped small-block builds needing stronger bottom-end support