Gotta love this SS/GA Dart

I can't fully explain it either, but NHRA has it listed in their classification guide.
http://www.nhra.com/tech_specs/classification/classfiles/1968DOD.xls

It comes in at 9.01 lbs per hp. "G" is 9.0 - 9.49.
A 340 is 10.51. 10.00 through 10.99 fall intp "I".

They even have a 440 Dart convertible listed! :dontknow:
Some weird stuff got slipped into NHRA over the years and somebody finds these unusual combos/loopholes from time to time!