Adjustable Carburetor Spacer Plates ('Sliders')

What happens here

The mechanic describes advanced modifications made to carburetor spacer plates, commonly known as 'sliders,' to bypass NASCAR's restrictor plate regulations. NASCAR rules mandated a specific diameter hole in the center of the intake manifold and a 1-inch block on top to limit engine horsepower. The 'sliders' were custom-fabricated plates with movable components designed to straighten the turbulent airflow caused by the restrictor plate. By aligning the airflow, these sliders could effectively increase horsepower by approximately 50 HP. Two main versions were discussed: one that could be pulled up by adjusting the carburetor studs, and another designed to be pushed into its optimal position by the high-speed air pressure itself. NASCAR eventually caught on to these 'sliders' and subsequently required them to be pinned or welded to prevent any movement. He also mentions a simpler trick: merely deburring the edge of a standard gasket, which surprisingly yielded a smaller, but still significant, 25 horsepower gain due to improved airflow dynamics.

Goal: Increase engine horsepower by optimizing airflow through restrictor plates.