If it takes the same bumper mounting brackets, it will be the same. If one takes the "regular" brackets ('73 and most '74 - if not all) and the other takes the "shock absorber" brackets ('75 - '76), the latter may be wider. They have a different carriage bolt mounting pattern and don't interchange.
I have a '75-'76 bumper at home I can measure, but not a '73-'74 to compare to.
