Actually they said the car started out as a V8 GT car and someone put a 6 in it which is odd but....its their money, their car....they can do with, what they want of course....
67 V8 GT car would have had a 273 in it , no big loss .
In 1967 I was offered a showroom new '67 Dart GT with 273 4-Barrel and Auto in a straight trade for my '67 Mustang GT 289 4 speed. I wish I had done it, I might still have that car. Instead I traded the Mustang for a Ford Fairlane with 390 2 barrel auto, that my ex-wife wrecked. You learn from your mistakes.