Griffiths valuation was a land valuation carried out on behalf of the then government by Richard Griffiths who had previously carried out a boundary survey of Ireland for Ordinance Survey maps of Ireland (1825-44). The land valuation which began in 1848 was completed in 1868. The valuation of the county of Londonderry (relevant to Kilkie) was completed in 1859.
A study of Griffiths valuation shows a number of Kilkie entries all dated as 1858 for Londonderry and 1862 for Antrim.
According to the map references George and James Kilky lived a few houses from each other and William Kilky was about 2 miles away. Whether the Kilky were related is unknown but is a possibility worthy of future study.
The nature of the Antrim Gilkie and Gilkie also requres more research.