The 'Test Mule' 68' Hemi Barracuda project actually started {first} in December 1967 {before the 68' Dart GTS 383 S/S project} but the Hemi Barracuda's and Dart's were not 'NHRA-legal' for Super/Stock until June 1968, one-week before the NHRA Springnationals.
The 68' Dart GTS 383 {440 conversion} was granted a 'special exemption' by the NHRA in mid-January 1968 so they could run in SS/EA at the Winternationals.