In the Welsh pack, it is all change in the front row with props Gethin Jenkins and Adam Jones packing down either side of hooker Matthew Rees and Ian Gough also returns to the second row to partner his Ospreys team-mate Alun Wyn Jones.
Regular captain Ryan Jones resumes his position in the starting forwards and he welcomes Martyn Williams back alongside him in the back row with Andy Powell retained at number 8.
Six starters from last week are on bench duty with John Yapp, Huw Bennett, Luke Charteris and Dafydd Jones providing cover for the forwards and Hook and Jamie Roberts joined by Warren Fury to cover for the backs.
"There is also a Triple Crown at stake and we know only too well in Wales that Grand Slams don't come cheaply - we've won two in the last decade and so all the pressure will be on Ireland to grab only the second in their history.
"With a healthy headstart you have to say Ireland are probably favourites to take the title, but we are confident we can come up with a win and who knows what will happen if we can get ourselves ahead in the game and that Millennium Stadium factor begins to kick in."
WALES (v Ireland): Lee Byrne (Ospreys); Mark Jones (Scarlets), Tom Shanklin (Cardiff Blues), Gavin Henson (Ospreys), Shane Williams (Ospreys); Stephen Jones (Scarlets), Mike Phillips (Ospreys); Gethin Jenkins (Cardiff Blues), Matthew Rees (Scarlets), Adam Jones (Ospreys), Ian Gough (Ospreys), Alun Wyn Jones (Ospreys), Ryan Jones (Ospreys) (capt), Martyn Williams (Cardiff Blues), Andy Powell (Cardiff Blues).
Replacements: Huw Bennett (Ospreys), John Yapp (Cardiff Blues), Luke Charteris (Newport Gwent Dragons), Dafydd Jones (Scarlets), Warren Fury (London Irish), James Hook (Ospreys), Jamie Roberts (Cardiff Blues).