In late-1966, when Plymouth introduced the GTX,
The plan was for the 426/425 HP 'Street Hemi' to be entered in
'A/Stock' for the 1967 NHRA Stock Class.
Plymouth even had a marketing campaign to emphasize the 67' Street Hemi
in A/Stock, where the 66' Belvedere 'Street Hemi's had dominated in 1966,
and held both ends of the A/S and A/SA National Records.
The Class weight break was 7.00 - 8.69 Wt/Hp.
But, the NHRA 'flipped' the Stock Class weight breaks, and changed
A/Stock to 8.70 - 9.49 Wt/Hp, which forced the 'Street Hemi' into
Super/Stock (SS/B).
