SBC Iron Eagle Block - 9.025 4.125/350

The SBC Iron Eagle Block - 9.025 4.125/350 by DART represents the foundation for serious small-block Chevrolet performance builds. Designed for engine builders, hot rodders, and mechanics pursuing high-horsepower applications, this cast-iron block delivers the strength and dimensional consistency required for street and competition engines. Whether you're rebuilding a classic muscle car, creating a modern restomod, or developing a dedicated race engine, this block provides the casting integrity and bore capacity necessary to support significant power increases while maintaining reliability.

Built from premium ductile iron, the SBC Iron Eagle Block features a 9.025-inch deck height and 4.125-inch bore diameter, making it compatible with 350-cubic-inch stroker and big-bore configurations. The larger bore allows for oversized pistons and performance ring packages, while the iron construction provides superior heat dissipation compared to aluminum alternatives—critical for sustained high-RPM operation and forced-induction applications. The robust casting design minimizes flex under load, maintaining critical tolerances across throttle cycles and supporting aggressive cam profiles, high fuel pressure, and turbo or supercharger boost. Weighing 218 pounds, this block offers exceptional strength-to-weight ratio for engine swaps and custom installations.

This block is ideal for builders targeting 500+ horsepower naturally aspirated or boosted engines, particularly in applications where thermal stability and long-term durability outweigh weight savings. The 4.125-inch bore pairs seamlessly with modern aftermarket crank, rod, and piston combinations, offering flexibility in displacement and compression ratios. Standard small-block Chevrolet accessories—heads, intake manifolds, and oil pumps—bolt directly without modification, simplifying sourcing and reducing build complexity. Installation requires proper machining and honing; professional engine builders should verify specifications against their rotating assembly and induction system before final assembly.