They opened the trip with a 35-10 win against a Namibia Invitation side and now take on a South Africa side that will want to make amends for a 45-13 defeat at Kimberley last July.
Head coach John Fletcher has brought in four forwards - a new front row of Nick Auterac (Oaklands College & Saracens), Koree Britton (Ivybridge College & Gloucester Rugby) and Anthony Brennan (Twyford C of E & London Wasps) and lock Dominic Barrow (Prince Henry's GS, Otley & Leeds Carnegie).
Fletcher praised the impact new captain Chris Walker and deputy Billy Vunipola have made since taking over the leadership of the side this summer.
"Chris has excelled in the way he's taken his first chance to lead the side and he's been really well supported by Billy on this trip," said Fletcher.
"The players have gelled together really well and been complimented wherever we've been for their behaviour on and off the pitch.
"Overall we're very happy with how everyone's performed so this was a tough selection to make. The players on the bench will still have a big influence on the game and we know South Africa are always going to be tough to beat at any level."
England Under 18
15 Ben Ransom (Tonbridge & Saracens), 14 Mark Jennings (Lymm HS & Sale Sharks), 13 Elliot Daly (Whitgift & London Wasps), 12 Tommy Bell (Bacup & Rawtenstall GS & Sale Sharks), 11 Charlie Walker (Oakham & Harlequins), 10 Joel Hodgson (RGS Newcastle & Newcastle Falcons), 9 Dan Robson (Hartpury College & Gloucester Rugby), 1 Nick Auterac (Oaklands College & Saracens), 2 Koree Britton (Ivybridge College & Gloucester Rugby), 3 Anthony Brennan (Twyford C of E & London Wasps), 4 George Merrick (Whitgift & Harlequins), 5 Dominic Barrow (Prince Henry's GS, Otley & Leeds Carnegie), 6 Will Skuse (Bryanston & Bath Rugby), 7 Chris Walker (Prince Henry's GS, Otley & Leeds Carnegie, captain), 8 Billy Vunipola (Harrow & London Wasps, vice captain)
16 Nathan Moris (Sedbergh & Newcastle Falcons), 17 Luke Cowan-Dickie (Truro College & Exeter Chiefs), 18 Kyle Sinckler (Epsom College & Harlequins), 19 Will Spencer (St Paul's Catholic & Bath Rugby), 20 Sam Northcote-Green (Dulwich College & London Wasps), 21 Henry Slade (Plymouth College & Exeter Chiefs), 22 Sam Hill (Ivybridge College & Exeter Chiefs), 23 Anthony Watson (St George's College, Weybridge & London Irish)