Cast Iron GM LSX Engine Block, 4.000" Bore 9.260" Deck Height, 4-Bolt Main Caps

Aeroflow Performance’s heavy‑duty cast iron GM LSX engine block is engineered as a rock‑solid foundation for street‑performance builds that demand precision, reliability, and value. This semi‑finished bare block is designed to accept your internal components with minimal machining, giving you a dependable platform to build a powerful, street‑tested engine.

Key features and benefits

• 4.000" bore with a 9.260" deck height and extended cylinder barrels, enabling up to 4.100" of stroke clearance for stroker kits.
• Priority main oiling system with two lifter crossover channels to improve oiling reliability under high RPM and demanding use.
• Thick Siamese cylinder bores and enlarged water jackets for enhanced durability and cooling efficiency in high‑output applications.
• Conventional 4‑bolt steel main caps with billet steel construction and splayed outer bolts for increased strength and rigidity.
• Compatibility with off‑the‑shelf standard components such as camshafts, timing chains, and oil pumps/pans, providing flexible build options.
• Robust stroker clearance while maintaining a solid foundation for a street/strip engine design.
• Cam Journal OD: STD 2.164" and Cam Location: STD for straightforward compatibility with common aftermarket parts.
• Electrical fuel pump; screw‑in freeze plugs; lifter bores:.842" for precise lifter fitment.
• Main Bearing Size: 2.558" and Main Bearing Bore: 2.750" to support higher power levels with solid oiling and bearing support.
• Oil Filter: No oil filter mounting on the block; Oil Pan: STD; Rear Main Seal: STD 4.527" fits standard configurations.
• Serial Number Location: Left Front & Main Caps for traceability; Starter: Factory OE Position; Timing Chain/Gears: STD; Timing Cover: STD.
• Weight: 110 kg (242 lbs).
• Pickup only—contact us for a shipping quote.

Technical specifications at a glance

• Bore: 4.000 inches
• Deck Height: 9.260 inches
• Main Caps: 4‑bolt steel with billet construction and splayed outer bolts
• Oiling: Priority main oiling with two lifter crossover channels
• Bores and cooling: Thick siamese bores and enlarged water jackets
• Cam/Timing compatibility: STD cam journal and STD cam location; STD timing chain/gears
• Lifter bores:.842 inches
• Main bearing bore: 2.750 inches; main bearing size: 2.558 inches
• Oil system: No oil filter mounting on the block
• Oil pan: STD; Rear main seal: STD 4.527 inches
• Weight: 242 lbs (110 kg); Pickup only

Why builders choose this LSX block

Designed for builders who want a reliable, no‑nonsense platform, this cast‑iron LSX block from Aeroflow delivers a robust foundation without sacrificing flexibility. The combination of a thick‑deck design, durable bore geometry, and strategic oiling features creates a platform that thrives under street and strip conditions alike. Whether upgrading a daily driver, assembling a weekend warrior, or aiming for predictable track reliability, this block pairs well with a wide range of components to deliver consistent performance. Note: This is a pickup‑only item—contact us for shipping quotes to your location.