Supercars recently confirmed the revised prototypes will be in action at the Launceston circuit across the Tasmania SuperSprint weekend.
Two-time champion Ambrose and 2007 title winner Garth Tander will drive the Ford and Chevrolet respectively in a series of demo and passenger ride runs from Friday to Sunday.
However it's now clear the running will continue on the Monday and Tuesday with two days of proper testing.
It will be the first full-blown test to be held outside of Queensland Raceway, after running at Winton last month was cancelled so the cars could undergo ergonomic and mechanical changes.
The driver line-up for the test isn't entirely clear, however Mark Winterbottom is understood to be driving the Camaro.
As revealed by Autosport last week, Gen3 testing will then move to Phillip Island on the week following the Australian Grand Prix.
Once again running is set to take place on the Monday and the Tuesday.
There is a shakedown for the Gen3 cars at Queensland Raceway planned for this Thursday, however it appears the Mustang may be sidelined due to partial factory closures at Dick Johnson Racing because of some positive COVID-19 cases.
Both DJR and Triple Eight are understood to have faced some COVID-related hurdles since staff returned from the Sydney SuperNight early last week.
A spokesperson told Autosport last week that preparations for Tasmania wouldn't be affected, however it now appears work on the Gen3 Mustang has in fact been impacted.
Both prototypes have been fitted with a mechanical gear shift system and undergone changes to the control chassis to improve ergonomics for taller drivers since they last ran.
