Carey/Currane/Foley

Hi, I am looking for information regarding my ancestors who came to NZ via Australia from Ireland

William Carey (my gt gt grandfather) was born in Maitland, Australia in 1861 and died in NZ in 1923.  His parents were Michael Patrick Currane Carey and Mary Munro (a famine orphan from Clonmel)

Michael was born in 1824 in Tralee, Kerry and died Dec 1864 in Horseshoe bend Maitland, Australia.  He came to Australia on the ship Haverny in 1849 as Michael Currane but the name then seems to become Carey.  Why would the name have changed?

Michaels parents are possibly Margaret Currane (born abt 1805/died 1863) and Michael Foley (born 1770)

How can I confirm Michael’s father is Michael Foley?

If anyone is researching this family or can help in anyway, I'd appreciate it.

Thanks

Susan Tyler