William Beck of Caskum Banbrige Area Northern Ireland

I'm looking for a William Beck his son William married Mary Linnon in 1848 at the Church of Ireland Loughbrickland William was borm in 1830 but I can't find anything about his father William.
There son John was born in Caskum 1864, John married Mary Shields in 1885 Belfast.
They moved to Belfast sometime after 1865.
I hope someone can hepl me finding William my email is rwbeck@telfort.nl