1911 census lists 11 homes in Dungonnell, 2 of which were occupied by McCanns. Access to those properties today should be from the modern Dungonnell Rd which goes up to the dam.
http://www.census.nationalarchives.ie/pages/1911/Antrim/Newtown_Crommelin/Dungonnell/
Archie McCann married Ellen Graham and his father was Donald (Daniel), a farmer.
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1905/10171/5700581.pdf
Family in 1901:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Crumlin/Dungonnell/929668/
Abstracts from the PRONI wills site:
The Will of Patrick M'Cann late of Dungonnell County Antrim Farmer deceased who died 4 October 1882 at same place was proved at Belfast by Daniel M'Cann and John M'Cann both of Dungonnell Farmers the Executors.
Administration of the estate of John M'Cann late of Dungonnell Glenravel County Antrim Farmer who died 20 September 1898 granted at Belfast to Patrick M'Cann Farmer.
Administration (with the Will) of the personal estate of Daniel M'Cann late of Dungonnell County Antrim Farmer who died 8 August 1907 granted at Belfast to Archibald M'Cann Farmer.
Probate of the Will of Archibald McCann late of Dungonnell County Antrim Farmer who died 29 September 1911 granted at Belfast to Michael McQuillan Farmer and Alexander Fyfe J.P.
Michael McCann was living elsewhere in 1901. Not certain he’s a native of Dungonnell:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Crumlin/Legagrone/929701/
They will likely have attended Glenravel chapel, as may any descendants alive today. You could write to the priest and ask if he can put you in touch with any McCanns from Dungonnell. (Maybe enclose several copies of a letter he can give them?)
119 Glenravel Rd, Martinstown, Ballymena BT43 6QL
0044 28 21758217