Based on the SAMTech.edu NHRA Factory Stock Showdown performance numbers from the first five races of the 2019 season, the NHRA Technical Department is reducing the minimum weight for all pre-2019 Chevrolet COPO and Ford Cobra Jet combinations from 3,525 lbs. to 3,450 lbs. Additionally, the 2019 Cobra Jet 327 combination upper supercharger pulley size will be increased from 3.750 inches to 4.000 inches and the 2015 Drag Pak 354 combination upper supercharger pulley will be decreased from 3.125 inches to 3.000 inches. As a reminder no other changes may be made to all approved superchargers, including, but not limited to upper or lower pulley sizes, gear ratios, cases, rotors, etc. All other permitted combinations in the SAMTech.edu NHRA Factory Stock Showdown will remain unchanged. These rule changes 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. The updated SAMTech.edu NHRA Factory Stock Showdown Rules and Procedures document can be found on NHRARacer.com under Rules/NHRA Factory Stock Showdown/Rules and Procedures.