Chris Waller's first trip to Perth six years ago dented his confidence that he could plunder a West Australian Group One race.

But any doubt is now a distant memory as the champion trainer prepares to chase three successive years of elite level victories at Ascot with Good Project and Mackintosh in Saturday's Railway Stakes.

Waller's first foray west was in 2010 with Triple Honour, the first of his now 65 Group One winners.

Triple Honour beat one runner home in the Railway before finishing sixth in the Group One Kingston Town Classic and fourth in the Group Two C B Cox Stakes.

"It didn't give me a lot of confidence," Waller said.

While it took four years for Waller to return, Moriarty proved to the triainer he could successfully pull off a Perth heist with an unlucky third in the Railway and victory in the Kingston Town.

"When you get success it makes it easier to go back," Waller said.

"That's why you see Golden Slippers, Melbourne Cups targeted by the same trainers every year because they have confidence in doing it.

"Going to Perth is no different."

He believes defending Railway winner Good Project is again the right horse to take west this year.

Good Project ran seventh in the Group One Cantala Stakes (1600m) at Flemington on October 29, with the horse blocked for clear running on the home turn.

"He's where he needs to be and Group One form where he was unlucky is as good as form you'll get going to Perth," Waller said.

Mackintosh was fifth in the Cantala.

Waller conceded Mackintosh was soft in the last 100m but attributed that to the horse being posted three wide during the race.

"The winner Le Romain came off his back through having cover," Waller said.

"I think if he had Le Romain's run, he would have been closer to the finish."

Stablemate Vanbrugh is likely to join Mackintosh in the Kingston Town (1800m) on December 3, with their trainer certain of only one crucial aspect of a successful western raid.

"I've worked out you've got to take a pretty good horse to be able to win," Waller said.