The NHRA Technical Department has released the latest version of the 2021 NHRA Hot Rod Heritage Racing Series Rulebook Supplement. The only changes made were to permit the FIA 8860-2010, FIA 8860-2015 and FIA 8860-2018 helmets as an additional option to the helmets already permitted by the rulebook supplement. The 2021 NHRA Hot Rod Heritage Racing Series Rulebook Supplement can be found under the Rules section of NHRARacer.com.