Caseys

Searching for ancestors of Peter Casey, son of John and grandson of Nicholas.  The family apparently came from Co. Tyrone and emigrated to America c. 1700.  Through my amateur family research, I have determined they may have lived in or near Clonfeacle parish although I have no proof.  There is no evidence of the family there from the 1660s Hearth Money Rolls but perhaps they were in Dunluce, Co. Antrim earlier with the O'Neills (a big guess).  At any rate, if anyone has information on these earlier Caseys, I and my distant cousins would certainly appreciate it.  I live in Ireland myself and wouldn't mind a wee dander around Tyrone / Armagh to see these townlands myself.  Thanks very much.