Darragh Moloney makes his second start of the tournament in the second row with Alex Wootton retaining his place on the wing.
Max Abbot, Rory Burke and Dan Goggin have started every game of the tournament to date, and all three join scrum half Ryan Foley on the bench.
Speaking ahead of the final test, Ruddock said,
"Trying to defeat a New Zealand team in Eden Park is a formidable challenge for any Irish team but we will give it our best shot"
Ireland U20 v New Zealand U20, IRB Junior World Championship 3rd Place Play-off, Eden Park, Auckland - Friday June 20th. KO 6:05am Irish time with live coverage on TG4 followed by full match highlights later that evening at 8:30pm.
15 Cian Kelleher (Lansdowne/Leinster)
14 Ciaran Gaffney (Galwegians/Connacht)
13 Garry Ringrose (UCD/Leinster)
12 Harrisson Brewer (Terenure/Leinster)
11 Alex Wootton (Garryowen/Munster)
10 Ross Byrne (UCD/Leinster)
9 Nick McCarthy (UCD/Leinster)
1 Peter Dooley (Lansdowne/Leinster)
2 Dylan Donnellan (UCD/Leinster)
3 Oisin Heffernan (Lansdowne/Leinster)
4 Darragh Moloney (Cork Constitution/Munster)
5 Ross Molony (UCD/Leinster)
6 Peadar Timmins (UCD/Leinster) Capt
7 Rory Moloney (Buccaneers/Connacht)
8 Frank Taggart (Belfast Harlequins/ Ulster) change from 8 to 7
16 Max Abbott (Cork Constitution/Munster)
17 Denis Coulson (Lansdowne/Leinster)
18 Rory Burke (Cork Constitution/Munster)
19 Stephen Gardiner (Lansdowne/Leinster)
20 Josh Murphy (UCD/Leinster)
21 Ryan Foley (Cork Constitution /Munster)
22 Conor McKeon (Lansdowne/Leinster)
23 Dan Goggin (Young Munster /Munster)