Why Aluminum

Cast-iron small-block Chevy engine blocks have defined the platform for decades, but their weight remains a constraint in performance applications. Speedmaster's aluminum small-block replacement addresses that directly - delivering a lighter block that accepts a larger stroke and resolves known tolerance issues found in factory castings.

Splayed four-bolt mains with billet caps.

Engineering Details

Jay Vurduzco, Operations Manager at Speedmaster, outlined the design decisions behind the block:

"We developed this block with the ability to accept a 4.155-inch bore. We also addressed the issue of the lifter bore dimensions. We've found that many times, the lifter bores in factory blocks were too tight, and we make sure that each bore is right. We also added priority main-bearing oiling so guys can run a dry sump oil system." - Jay Vurduzco, Operations Manager, Speedmaster

Replaceable steel sleeves.

Features

• Splayed four-bolt main caps
• Main bearing priority oiling
• Chamfered oil passages
• Accepts all factory small-block components
• Weighs 113 pounds in the shipping crate

For builders looking to reduce engine weight without sacrificing compatibility, Speedmaster's aluminum small-block is available now. View the full specifications at speedmaster79.com.

About Speedmaster

Founded in 1979, Speedmaster is a vertically integrated performance company delivering complete, engineered performance systems across engines, drivetrain, and forced induction. With more than 500 employees across three continents and over 25,000 parts designed, engineered, and manufactured in-house, Speedmaster operates as a unified brand built on engineering precision, long-term thinking, and measurable results. Learn more at speedmaster79.com.