Hello. I cannot help you directly with your search, although we share a common ancestor in Joseph Grant III, b. 1716. My descent from him is:
1. Joseph Grant IV, b. 1742 d. 1815, m. Hannah Drowne
.2. Joshua Grant, b. ???? d. 1822, m. Mary Martin
..3. Cyril Read Grant, b. 1807 d. 1846, m. Abby Fales Mason
....4. Henry Martin Grant, b. 1842 d. 1922, m. Nancy Arda Rorison
.....5. Sarah Mabel Grant, b. 1875 d. 1919, m. Richard Fenner Monges
......6. Adele Grant Monges, b. 1909 d. 1973, m. John Walter Davison (my parents)
My documentation past Cyril Read Grant is not strong, and of course, my Y-DNA is in the Davison line, not Grant (I just submitted a sample to Family Tree DNA for analysis). However, I have male Grant cousins whom I hope to ask to submit a Y-DNA sample, and if one of them does, we should be able to confirm our family connection at Joseph Grant III. I would be interested in any genealogical documentation you may have on Joseph Grant III and his descendants, and anything you may find about the line back to Edward Grant.
Are you a member of the FTDNA Grant family project? I just checked, and two kits submitted there claim Edward Grant 1632-1682 as their paternal ancestor. Perhaps one has the lineage we both seek.
Looking forward to hearing from you,