Based on the FLEXJET NHRA Factory Stock Showdown performance numbers from the first 5 races of the 2023 season, the NHRA Technical Department is reducing the supercharger overdrive by changing the upper supercharger pulley for the 2019 Ford Cobra Jet with iron blocks from 3.500 inches to 3.750 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.