Stanaway will partner an in-form Shane van Gisbergen in the #97 Red Bull Camaro at the Sandown 500 and Bathurst 1000 later this year.
The T8 deal comes amid a career revival for Stanaway who walked away from professional motorsport at the end of 2019 after two tough Supercars seasons with Tickford Racing and then Garry Rogers Motorsport.
He was tempted back to the sport by Boost Mobile boss Peter Adderton last year with a Bathurst 1000 drive alongside Greg Murphy in a Boost-backed wildcard entry.
Stanaway was hugely impressive across the Bathurst weekend, the highlight his fourth place on the grid, and revealed to Motorsport.com that the return had piqued his interest in a proper comeback.
He was then poised to drive a full-time Boost car in Supercars this year, only for that plan to be skittled when Supercars wouldn't release an entry to Adderton.
Having briefly spoken to Triple Eight about potentially replacing Tander before Bathurst last year, he was then the obvious choice when Tander eventually jumped ship.
While this plum T8 drive will be the perfect opportunity for Stanaway to further showcase his ability, the 31-year-old admits it may not ease his path back to a full-time ride.
Instead, he thinks it will make him more picky when it comes to potential season-long options.
"I'm not too sure," he told Motorsport.com when asked if a full-time ride is still his ultimate goal.
"I think it will be more of a question for post-Bathurst this year.
"If I'm being honest, having such a good co-drive does make coming back full-time a lot more difficult. When you've got, I guess, arguably the best co-drive in the field, it limits the roles that you would be open to accepting full-time.
"So, yeah, it will be a matter of seeing what's on the table come the end of the year."
At the same time, Stanaway says the door for a full-time Boost entry in 2024 is still ajar, while he and Adderton are continuing to explore solo-driver wildcard options in Supercars this year.
Should a sprint round wildcard come off, Stanaway would likely run as a satellite T8 entry, with Adderton having committed to buying a Gen3 Camaro from the Brisbane-based team.
"Yeah we're going to try and do as many wildcards as we can with that car," said Stanaway. "And then see where it goes from there.
"Obviously they still want to run a car full-time in 2024 so doing the wildcards could be a good launchpad for that. It's just a matter of waiting to see what rounds are available and how it goes from there."
Stanaway is planning to attend the majority of events with T8 this season even when he's not racing to help sharpen the learning curve with the Gen3 hardware.
He'll also be a key fixture during T8's test and ride day programme throughout the season.
"I think the plan is for me to be at as many [test] days as possible, I guess to mitigate the fact that the co-drivers will be limited with running with the new car," he said.
"I'm not sure what the plan is yet but I'll try and get as many laps in as possible. Even if I'm not driving I'll try and be at as many days and as many rounds as possible so that I can learn about the new car even if I'm not driving it."
Stanaway will kick off his working relationship with T8 early next month with a seat in the squad's Pro-Am Mercedes at the Bathurst 12 Hour alongside Jamie Whincup and Prince Jefri Ibrahim.
He sampled the T8 AMG for the first time at The Bend Motorsport Park in South Australia yesterday.
