Speedmaster 1-274-034 I-Beam Pro Connecting Rods 6.135" 4340 Chromoly for Chevy BBC 454

Speedmaster 1-274-034 I-Beam Pro connecting rods are engineered for high-performance Chevy big block 454 applications producing 1000+ horsepower. Manufactured from aircraft-grade 4340 chromoly steel, these rods combine proven I-beam design with H-beam strength characteristics for maximum durability in demanding racing environments.

Key Specifications:

• Center-to-center length: 6.135 inches
• Big end bore: 2.200 inches
• Pin bore: .990 inches (wrist pin bore)
• Material: Aircraft 4340 chromoly steel
• Fasteners: ARP 2000 series connecting rod bolts included

Performance Features:

• One-rib cap design provides increased strength and superior bearing support
• Polished beam surfaces eliminate stress risers and improve fatigue resistance
• Profiled design with clearance for long-stroke crankshaft applications
• X-ray and ultrasonic inspected for internal integrity
• Shot peened and stress relieved on all surfaces for enhanced durability

ARP 2000 Series Bolts:

• Precision CNC-machined to exacting tolerances
• Heat-treated with rolled threads for maximum strength
• Up to 10 times more fatigue strength than OEM fasteners
• Engineered to handle extreme combustion pressures in high-performance engines

These connecting rods are designed as a direct upgrade for Chevy big block 454 engines and are ideal for street/strip, drag racing, and high-output naturally aspirated or forced induction applications. The combination of premium 4340 steel construction and ARP 2000 hardware ensures reliable performance under extreme loads.