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SKU: B627144030 | UPC: 793348041032
Eagle Pro Street Balanced Rotating Assembly - Chevrolet Small Block 408 ci (4.030" Bore x 4.000" Stroke)
The Eagle Pro Street balanced rotating assembly for small block Chevrolet engines delivers a complete, internally balanced 408 cubic inch kit built around a 4140 forged steel crankshaft and 4340 forged I-beam connecting rods. Designed for street performance and moderate racing applications up to 700+ hp, this kit includes forged pistons, plasma-moly file-fit rings, and high-performance bearings – providing a reliable foundation for stroker 350 builds with improved displacement and torque.
Key Features
- 4140 Forged Steel Crankshaft: 4.000" stroke with 350 main journals (2.448") and standard SBC rod journals (2.100").
- 4340 Forged I-Beam Rods: 6.000" length with 7/16" ARP 8740 cap screws – rated for 700+ hp.
- Forged Pistons: 4.030" bore, dish or flat top (compression ratio varies by head/chamber).
- Plasma-Moly File-Fit Rings: 1/16" - 1/16" - 3/16" ring pack for low friction and excellent sealing.
- Clevite H-Series Bearings: Tri-metal rod and main bearings included.
- Internally Balanced: No heavy metal required – ready for assembly.
- RPM Capability: Safe to 6,500+ RPM with proper components.
- Made in USA: Manufactured and assembled by Eagle Specialty Products.
Product Notes
- Part number: B627144030 (408 ci Pro Street kit).
- Crankshaft: 4140 forged steel, non-twist forging, nitrided for durability.
- Rods: 4340 forged I-beam with ARP 8740 bolts – bushed for floating pins.
- Pistons: Forged 4032 or 2618 alloy (varies by batch) – typically -18cc dish for ~10:1 compression with 64cc heads.
- Balanced to ±2 grams – ready for installation.
- Total kit weight approximately 135-145 lbs.
- Requires 4.030" bore block (350 block bored .030" over).
Installation Notes
- Professional engine builder assembly required.
- Clearance check all components (piston-to-valve, rod-to-cam, etc.).
- Use high-zinc break-in oil and follow proper ring seating procedure.
This Part Fits
| Engine | Block | Bore | Notes |
|---|---|---|---|
| Chevrolet Small Block V8 | 350 ci (4-bolt or 2-bolt main) | 4.030" | 1967-2002 SBC blocks |
| Stroker Builds | Dart, World, GM, etc. | 4.030" | Requires clearancing for 4.000" stroke |
Why Choose Eagle Pro Street?
- 30+ years of crankshaft and rotating assembly expertise.
- Pro Street series offers forged 4140 crank and 4340 rods at an affordable price point.
- Trusted by engine builders for street and strip 408 SBC builds.
Frequently Asked Questions
- Q: What compression ratio?
- A: Typically ~10:1 with 64cc heads and -18cc dish pistons – confirm with your heads.
- Q: Is it externally balanced?
- A: No – fully internally balanced for use with neutral balance flexplate/flywheel.
- Q: Does it include a balancer or flexplate?
- A: No – crankshaft only; uses neutral balance damper and flywheel.
Shipping & Handling
- Method: Freight truck (heavy crate).
- Package Weight: Approximately 160–180 lbs.
- Crate Dimensions (approx): 42" × 24" × 24".
Eagle
Eagle Specialty Products has been a trusted manufacturer of high-performance forged and billet engine components for over 35 years, producing connecting rods, crankshafts, piston rings, and rotating assembly kits that engine builders rely on when stock parts are no longer adequate for the power level being chased. The brand's 4th generation H-beam connecting rods, known as the 4D design, address the most common failure points in previous-generation rods by increasing big-end rigidity through thicker webbing and an improved beam profile that resists bending under high cylinder pressure. Eagle rods are 100 percent CNC machined from 4340 chromoly steel, include ARP 2000 rod bolts as standard, and are popular for both street-strip builds and dedicated track-day engines on a range of domestic V8, LS, and sport compact platforms. Builders who want proven rotating assembly reliability without custom billet pricing consistently choose Eagle as their go-to rod supplier.Popular UpgradesEagle'...
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