Never, period. The body designs changed in 67. Check closely to see if your vins have been changed. Major issues with the DMV and the cops. Also, someone may have put a 66 cab on a 67 frame and used the tittle to the 67 frame. This is considered a 67 in many states as tittles could go with the engine (rarely used) cab or frame. Even if your 66 is tittled as a 67, never refer to it as so, it irritates those who know the differance.
