Ferris is currently just one point ahead of defending national champion Cooper, with fellow Australians Todd Waters and Luke Styke not too far behind in third and fourth position respectively.
Kiwi heroes Carter, Mangakino's Kayne Lamont and Taupo's Brad Groombridge make up the top seven in this class and all these three riders have an enviable reputation on this circuit.
Perhaps home turf knowledge will assist them on Saturday.
Cooper, Harwood, Carter, Lamont and Groombridge have all represented New Zealand as part of the three-rider Motocross of Nations team in past years - racing the world's elite in countries such as Italy, France, the United States and Belgium - and so the pressure of a big occasion is not likely to unsettle them.
The MX2 (250cc) class should provide another explosive confrontation.
It is tight at the top in this category, with defending champion Harwood just 11 points ahead of his nearest challenger, Walsh.
If Walsh wins every MX2 race and Harwood finishes runner-up each time, as happened at the previous round at Himatangi two weeks ago, then Harwood will retain his title by just two points.
If not, it's anybody's guess where that trophy will go.
In addition to Walsh, Waitakere's Ethan Martens, Te Puke's Logan Blackburn or Reporoa's Hadleigh Knight could be expected to win the day, with Cambridge's Trent Collins and visiting Australian Kaleb Barham also possible winners.
It is intense at the top of the 125cc class too, with just eight points separating Taihape's class leader Hayden Smith from Karaka's Kurtis Lilly.
Racing kicks off about 10am.
