CNC machined from billet aluminum, these spacers are available in 16 different versions and are ultra-light. Each one of our 4-hole and open spacers are precision bored to match carburetor base plates for a precise fit. All of our spacers are dyno tested so the high performance enthusiast can fine-tune his engine for maximum performance. Spacers are available in 1/2", 1" and 2" sizes for 4150 and 4500 series carburetors. Item is in stock.