Eagle 638713820 Competition Rotating Assembly 8-Cylinder Forged 4340 Crank 3.900in Stroke

The Eagle Specialty Products 638713820 is a competition-grade rotating assembly engineered for high-performance 8-cylinder engine builds. Built around a 3.900" forged 4340 steel crankshaft with a 58-tooth reluctor wheel, this assembly is designed for LS-based platforms and delivers the bottom-end strength required for serious street/strip and racing applications.

At the core of this kit are 6.125" forged 4340 I-beam connecting rods secured with 7/16" ARP 8740 bolts, paired with forged 4032 DSS -29cc inverted dome pistons — a combination that provides exceptional strength and thermal stability under high cylinder pressure.

Key Features:

• 3.900" forged 4340 steel crankshaft
• 58-tooth reluctor wheel for modern EFI compatibility
• 6.125" forged 4340 I-beam connecting rods
• 7/16" ARP 8740 rod bolts
• Forged 4032 DSS -29cc inverted dome pistons
• 8-cylinder (V8) rotating assembly kit
• Test-fitted in-house by Eagle Specialty Products to ensure component compatibility

Eagle rotating assemblies are test-fitted at the factory to verify proper fitment and clearances before shipping. Each assembly also includes engine bearings and piston rings suited to the intended application. This kit is sold unbalanced — professional balancing by a qualified machine shop is required before installation.