91-26350. There was a large thread about the 160th SOAR Blackhawks in Somalia over the ARC Forum awhile back, the tail number was posted there.
http://www.aircraftresourcecenter.com/forums/index.php?s=01267158d0a52094b13e9b6d10e36d6e&act=ST&f=17&t=1351&hl=durant&st=
HTH,
Albert