Gribbin is still a common name around Portglenone and you can find Gribbins by either going to Google and printing gribbin portglenone and getting names or finding Gribbins through British Telcom <bt.com> directory assistance. You have to register and get a password. Likely there is some Gribbin in Portglenone who will have some family history. You should be able to get the appropriate church records through your nearest branch of the LDS library. There is some variation in name spelling - Gribbin, Gribben,Gribbon.
Some were Protestant and others R.C. There are fragments of the 1851 Antrim Census on the net which would be worth going through. Just print gribbin portglenone on Google and see what you get. There were Gribbens at Rasharkin I know.