Based on the Holley EFI Factory X performance numbers from the 2023 season the NHRA Technical Department is reducing the supercharger overdrive by changing the upper supercharger pulley for the 2019-2023 Chevrolet COPO from 3.125 inches to 3.375 inches. 2021 Dodge Drag Pak from 3.375 inches to 3.500 inches. This rule change will go into effect immediately. NHRA reserves the right in the future to make additional rule changes to control performance and maintain parity in the category.