I just recently got my Big Y-700 results (surname = Callihan) which confirmed I'm on the I2 Isles Scotland/Ireland line: L126 -> S7753 -> Y4751 -> BY48168 -> Y31616. I have a McEvoy as a match (I-BY48168, 811498 shared variants). Y31616 is a direct branch of BY48168 (one step up). He lists Callaghan as an ancestral surname, as well as other surnames, Quinn and Byrne (I-Y139612 and I-Y63570, both offshoots from Y4751), with which I also match. So, we might very well be distant cousins.
If you haven't upgraded to the Big Y-700 test, it could nail down that BY48168 prediction and possibly supply you with a good number of Big Y matches (I've got 116 matches).
Hi, it is so fascinating what DNA can find out. I will have to try my best to upgrade to BigY700 in the new year.