Advance Lockout Plate - GM HEI Dist.

The PROFORM Advance Lockout Plate for GM HEI Distributors is a precision-engineered component designed for engine builders and performance mechanics who demand reliability in high-performance ignition systems. This lockout plate is essential when converting or upgrading GM HEI distributor assemblies, particularly in street machines, race engines, and custom restorations where ignition timing control and mechanical accuracy are non-negotiable.

The Advance Lockout Plate works by mechanically restricting unwanted advance movement within the HEI distributor housing, preventing vacuum or centrifugal advance mechanisms from causing unpredictable timing shifts during critical engine operation. Its compact and lightweight design minimizes rotating mass while maintaining structural rigidity to handle high-RPM environments. The precision fit and finish ensure it seats flush within the distributor assembly without requiring modification to core components, making installation straightforward for experienced technicians.

This lockout mechanism is particularly valuable when running custom ignition curves or when you need to lock timing at a specific advance point for tuning consistency. Mechanics and engine builders preparing GM HEI-equipped engines for performance applications will find this product indispensable for achieving optimal ignition timing.