Based on the FLEXJET NHRA Factory Stock Showdown performance numbers from the Toyota NHRA US Nationals in Indianapolis, IN, the NHRA Technical Department is increasing the supercharger overdrive by changing the supercharger rear jack shaft pulley and rear cog pulley for the 2019-2023 Chevrolet COPO 350 from 32 teeth to 34 teeth on the jack shaft pulley and from 34 teeth to 32 teeth on the supercharger pulley. 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.