I have recently learnt from a Levack who lives in Northern Scotland, that the name there (also Levach) is thought to be a Maclea/Livingstone clan name peculiar to that region. -ack or -ach is a common name ending in that region, and the -lev comes from an old version of the Maclea name.
So I'd like to inform you about the DNA project which covers all related surnames of that clan:
http://users.skynet.be/lancaster/Discussion%20Maclea.htmThis is not a commercial announcement. I am a Livingstone genealogist and the project is run by participants like myself. We already have one Levack (results not yet in).
Regards
Andrew Lancaster