McEvoy will attempt to hand Waller the Melbourne Cup, the only glaring omission from the star trainer's resume, when he rides Finche in the $A7.75million ($NZ8.3million) Flemington feature at 5pm.
To do it, the two-time winner must get Finche to master Cross Counter, the lightly raced British stayer who powered home to win the race last year.
McEvoy has switched camps, and Norwegian-born William Buick is booked to ride last year's winner.
Moving into the corner of the biggest star in Australasia's training ranks was an easy decision, Sydney-based McEvoy said.
"Chris Waller is going to win it one year, I'm sure, and it could be this year,'' McEvoy told Australian media.
"These guys are star trainers so you've got to be in their camp when you think it's right.
"I think Finche can run a great race for everyone.''
McEvoy has already made dreams come true for another New Zealand-born trainer. He enabled transtasman trainer Mike Moroney to win the race with Brew in 2000.
Finche had done everything right in his preparation, McEvoy, who his seeking his fourth win in the race, said.
"He showed he's in fine fettle the way he finished off his work, so he can run a great race, I reckon.
"He's come through a nice effort in the race last year and he has shown this preparation that he's in good form.''
The French-bred Finche ran fourth behind Cross Counter in last year's cup after being bought by Waller.
Last year, Cross Counter carried the light weight of 51kg. Today the Charlie Appleby-trained galloper will carry 57.5kg, 3.5kg more than Finche (54kg).
McEvoy hopes that is enough for Finche to turn the tables on last year's winner.
"He's that little bit older now and he's acclimatised to our conditions,'' McEvoy said.
There is little apprehension in the Appleby camp about their horse's weight rise.
The stable maintains Cross Counter has returned a bigger and stronger prospect.
"The weight has gone up a lot from last year, but of the horses in and around him with chances, we aren't giving away too much weight,'' Appleby's foreman Chris Connett told Australian media.
"I think we're just as confident as last year. He's fit, firing and really flourished since we've come to Australia so we're happy.
Cross Counter is one of 10 international contenders from outside Australasia.
Among them is Japanese galloper Mer De Glace, who has a chance to make history for jockey Damian Lane.
The Victorian jockey will be attempting an incredible hat-trick of group 1 wins in a season. He rode Mer De Glace to victory in the Caulfield Cup, and his stablemate, Lys Gracieux, to win the Cox Plate.
Lane also won the Golden Slipper in March.
The prospect of such a special treble was ``not going to change how I ride the horse, it's not going to change how the horse is going to run, so what will be will be'', Lane told Australian media.
"It's been a great carnival, a great year, and I've been lucky to get on some quality Japanese gallopers and I know I'm on the right horse in the cup.''
Mer De Glace and Finche were rated the $7.50 equal favourites in New Zealand betting yesterday.
New Zealand hopes will be carried by the Southland bred-and-owned The Chosen One, who has drawn barrier 18 in the field of 24 starters.
The 4yr-old entire is trained at Cambridge by Murray Baker and Andrew Forsman, and won the Herbert Power Stakes (2400m) three starts ago. He will be ridden by Tim Clark.
Cross Counter was rated the $13 fifth-favourite behind Constantinople ($9) and Vow And Declare ($12).
