It will mean much more competitive two-car racing with close finishes for the fans to watch, with both competing cars reaching a maximum speed of around 200mph (321.869kmh).
"They're drag cars, not road cars," Rivers said.
"Things just over-powered it in the 1990's and 2000's."
Rivers workmate Dean Scott is entering his Chevy pickup, which could be a leading contender for the series.
Also entering the 22-car field is Whanganui's Rhys O'Mahony with his 1951 FX ute, and Waverley's John Hooper, a regular on Taupo Quay for the Wanganui Road Rodders' Street Drags.
Rivers said 'Wild Bunch Wars' is the brain child of Auckland's Ryan Sheldon, who worked hard to secure sponsors and get the event on the schedule at Masterton and Meremere.
In the last two decades, the growing popularity of the professional Doorslammer class, which Rivers said was a "free for all" in terms of building and spending to increase the power in their methanol-fuelled engines, meant the Wild Bunch cars could no longer compete alongside the newer vehicles, which took a lot of amateur racers out of the sport.
Rivers said the cars didn't completely disappear, but those who kept going were shunted into various other lesser divisions at the big events.
"A lot of Wild Bunch cars got put in the shed because they couldn't even qualify.
"[This division is] getting all those old cars that ran 7-8s.
"It's getting the money out of it, which killed the class years ago.
"It's worked, because it's got 22 cars in the field. The big guys can't come and ruin it.
"It's not one car 200 miles down the track before the other one leaves."
Wild Bunch Wars has been organised by the Wild Bunch NZ in association with Kumeu Classic Car and Hot Rod Festival.
The invited field consists of some new cars as well as classic originals from back in their heyday.
"The diversity and unpredictability of the original class remains, upgraded and improved to create a show not previously seen," said the press release.
"From wild smoky burnouts to insane edge of your seat passes, the Wild Bunch is just that."
The first day on Saturday, January 4 will consist of a heads up "teams race", with the Sunday event being the main individual battles.
There is a prize pool of over $4000.
More details are available on the Wild Bunch NZ Facebook page.
Locally, the 34th annual Street Drags will be held on Taupo Quay on March 1.