"He's very fit and ready for his Grand Final," Waller said of Sixties.
"He's had the two runs back from a spell and both have been pretty impressive to my eyes.
"After the Golden Rose it was either the Australian Guineas or Randwick Guineas and we've got Autumn Boy in Sydney, so we decided to split them up.
"He needed to run well first-up, which he did, and he needed a run left-handed, which he did well, and he's kept improving.
"It's another step up on Saturday, but he's the right horse to be able to do it."
Damian Lane, who partnered Sixties in his C S Hayes victory, rides the colt again on Saturday before commencing a careless riding suspension.
Sixties must overcome the widest draw, barrier 10, and the presence of Victoria Derby winner Observer who resumed with an impressive win in the Autumn Stakes (1400m) at Caulfield on February 7.
Waller said Sixties was versatile and more importantly has a great temperament.
"He's led and won Stakes races before and he's come from back and he's sat wide," Waller said.
"The beauty of Sixties is, he's got a great temperament. Wherever Damian wants to be, he'll be responsive and he will settle if he does ask him a question early.