Hemi Cast Iron Hemi Siamesed-Bore Block

Siamesed-Bore 426 Hemi® Blocks give engine builders flexibility. Blocks can be bored to the stock size of 4.25", but are specifically designed to be bored larger. Remember to sonic check each block if you approach or exceed the 4.50" bore diameters.


• 100% CNC machined for accuracy and quality
• Brand-new castings made from high nickel alloy cast iron
• Thicker deck surface for improved rigidity and gasket sealing
• Ductile iron main caps, which are cross-bolted on the 3 center caps on all the blocks

• Stock 10.72" deck height allows for installation of all standard components
• Machined to accept all standard production pieces, such as heads, manifolds, water pumps,tappets, cams and distributors

• Machined and cast in various configurations to meet your specific requirements.

• P5007627AB features a raised cam (0.250") for longer strokes and more cubic inches. Stroke size of up to 4 1/2" may be used. Requires special UGL camshaft (P5007713), cam gear and cover set (P5007657), special oil pickup and intermediate shaft modifications.

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