Vanthoor will contest the three-hour race as a one-off for Century Motorsport aboard its BMW M4 GT3 on the 26-28 April, amid WEC duties for the German manufacturer in the hypercar class.
The drive was originally for Dan Harper, but in March Leung’s former co-driver secured a last-minute call-up for the British GT season in one of Century’s other BMWs - so, Vanthoor was eventually selected for Silverstone.
“It will be special,” said Vanthoor of his forthcoming debut, which will be live and free on Motorsport.tv. “Looking at last year’s performance from Darren and Dan, there’s not much we can do to do better than that, so for sure we will try and do the same.”
Silverstone will be Leung’s first British GT race since clinching the championship in the 2023 season finale having skipped this year’s opening weekend at Oulton Park.
It came after he and Harper originally decided to not defend their crown, but a one-off round at Silverstone was always the plan until the 23-year-old secured a seat for the season.
“I would love to have done the Silverstone 500 with Dan,” said Leung, who won the race with Harper in 2023.
“Circumstances changed and we had to assess other options. Fortunately, BMW has a very deep pool of factory drivers and Dries was available for Silverstone.”
Vanthoor should still bring a lot of qualities though as the 25-year-old is a three-time GT World Challenge Europe Sprint Cup champion and 2017 Le Mans 24 Hours winner in the LMGTE-Am class.
“Speed-wise, he’s top tier,” added Leung. “But I’ve always admired his approach. I know he will be flat out at every opportunity and that’s something I really appreciate.
“We’re not racing for points, a result or even a podium, I want to defend that win and that’s the mentality we’ll have.”
It has been an otherwise slow start to Century’s British GT campaign as its best result at Oulton Park was ninth in the first of two one-hour races that weekend.
Elsewhere, Optimum Motorsport is running a second McLaren 720S GT3 for Silverstone with Le Mans Cup duo Fran Rueda and Andrew Gilbert as its Silver-Am crew.
It is part of a 44-car grid for British GT's second race meet of the season, which also features the series return of 2011 GT Academy winner Jann Mardenborough who is sharing one of Team RJN’s McLaren 720S GT3s with Chris Buncombe.
