67as well.
...unnless you're calling pre-67 "early A".
Further detail related to the Question, the 66 273 emblem looks like the 67 emblem, but is flat compared to the 67 with a body contour in it. 65's just had the V8 emblem
I've never heard of them (273 four barrel) available at any time in 68 (but parts were still readily available). The 340 was out from the beginning of production...
If you look in The front of an original 1968 service manual they still list 273 HP as engine code E. I doubt any were made. Always struck me as funny.
The 273 hipo was available in 1968 and not only A bodies- recently a 68 Dart ragtop was for sale here in MD- may still be on CL