Casting Identification on 67 273-4

Dave...welcome to the forum. My '67 Dart also has casting 2806030,but mine says 273-7 after,so,in the absence of a 7bbl carb, I would have to say that the "-2" doesnt mean 2bbl :-)....Sorry, I couldnt resist!!!
I have been told that this number is the amount of times that a particular mold was used. If you check the area on the front of the drivers side of the block just below where the head and block meet,there should be a combination of a letter and some numbers stamped,in your case,it should say "C273".

Hope this helps