Hi Marybeth,
Have you visited the Irishmcgoff.com website? If not, please check it out. Most Hehirs appear to have Clare or Limerick roots, but the famine and limited landholdings caused many to move on. Post whatever info you have, including all birth dates, even approximate, emigration dates, arrival points, etc. Another site to visit is clarelibrary.ie. Check the genealogy, people and places listings. I haven't found anything to match it in other counties, and there is an abundance of information on the Hehir name. Good luck!