Assuming your ages are correct he would have been 5 or 6 in the 1881 census. So looking for John or William aged 4 - 7 :
There are five John's, 4 Williams
Ignoring those whose father is not William, this looks like your best bet:

1881, Braddan, district 3, schedule 83, Castleward
William Callow, head, married, 24, agricultural labourer, Conchan
Sarah, wife, married, 27, Conchan
William J, son, 6, scholar, Conchan
Sarah J, daughter, 6, scholar, Conchan
Thomas A, son, 4, Conchan
Netter, daughter, 3, Conchan
Robert, son, 2, Conchan
Harriet, daughter, 6 months, Braddan

This is the family of William Callow and Sarah Corlett who marriedm 20 Oct 1874 at Onchan