Speedmaster LS 4 Bolt 102mm to LS1 85mm 3 Bolt Throttle Body Adapter 1-539-001

The Speedmaster LS 4 Bolt 102mm to LS1 85mm 3 Bolt Throttle Body Adapter (MPN 1-539-001) is a precision-engineered fitment solution designed for engine swap and custom build applications. This adapter bridges the bolt pattern and bore diameter differences between late-model LS series engines and earlier LS1 throttle body configurations, allowing seamless integration of modern LS components onto LS1 engine platforms without extensive modification.

Built for reliability and ease of installation, this adapter maintains proper throttle body alignment and sealing surfaces required for accurate fuel-air mixture control. It is ideal for street rodders, engine swap enthusiasts, and performance builders who want to upgrade or interchange throttle body components while preserving factory-style fitment. The straightforward bolt-on design eliminates custom fabrication, reducing installation time and ensuring consistent results across builds.

Key Features & Benefits

• Dual Bolt Pattern Design: Converts LS 4 Bolt 102mm configuration to LS1 85mm 3 Bolt fitment for direct adapter compatibility.
• Precision Engineering: Maintains proper throttle body alignment and sealing surfaces for reliable operation.
• Bolt-On Installation: No custom fabrication required; bolts directly to existing engine and intake manifold mounting points.
• Engine Swap Ready: Purpose-built for LS-to-LS1 engine swaps and custom builds requiring component interchange.
• OEM-Style Fitment: Delivers factory-grade compatibility and appearance for professional installations.

Specifications

Ideal Applications

• LS to LS1 engine swap projects
• Custom engine build installations
• Throttle body component interchange on performance builds
• Street rod and hot rod engine swaps