Not to discount the 290/225 4-Barrel 'N' Code
In 1968,
the 67' Rambler American 290/225 4-Barrel car was classed in
J/S or J/SA (12.50- 12.99 Wt/Hp).
440 2-Door Sedan (#2817 lbs. ~ 225 HP = 12.52 Wt/Hp)
That was one-hell-of-a-competetive-class...........
1968 National Records;
J/S,,,,,,,,,,,,13.14 @ 105.50 MPH
J/SA,,,,,,,,,13.62 @ 102.43 MPH