The GM squad has been working on a split shakedown for its two Gen3 Camaros with Mark Winterbottom hitting the track tomorrow (Wednesday) and then Scott Pye on Thursday.
However the team has opted to combine the shakedowns and run both cars on Thursday.
A team spokesperson confirmed that the decision was made to ensure the finishing touches could be put on the cars across the next 24 hours.
The delay will also allow the crew to rest the night before the shakedown following what has been a frantic off-season build.
Following the shakedown the cars will head to Sydney for next Wednesday's all-in, pre-season test at Sydney Motorsport Park.
This is the latest in a series of postponements and delays for Gen3 testing as teams scramble to complete builds ahead of the new season.
Bad weather in Queensland, meanwhile, has seen Dick Johnson Racing and Matt Stone Racing push it latest round of shakedowns, planned for today, back to tomorrow.
Team 18 is one of two teams to have not shaken down a single Gen3 at this stage, the other being Walkinshaw Andretti United.
WAU is expected to roll out both of its brand new Mustangs at Winton tomorrow.
There are cars on track at Winton today, with Tickford running Cam Waters and Thomas Randle, Erebus shaking down Will Brown's Camaro, and all four Brad Jones Racing Camaros in action for the first time.
