The Australian series has been working through an official parity review that was triggered following the Darwin Triple Crown last month.
As it stands the Chevrolet Camaro has been first across the line in every race since the beginning of the Gen3 era this year.
The review has largely been focussed on aerodynamics thanks to renewed suspicions that aero balance has been affecting rear tyre life for the Ford Mustangs.
After crunch meetings at the start of last week, aero testing took place with Tickford Racing at Winton and Dick Johnson Racing at Queensland Raceway.
CFD work has continued with Supercars' engineering partner D2H in the UK with the latest round of data landing this evening.
That has now been reviewed with a recommendation to modify the position, span and angle of the rear wing, as well as increase the size of the boot spoiler.
The changes will be made in time for the Townsville 500 this weekend.
It is expected the change will improve the rear downforce of the Mustang while braking and help make it more competitive compared to the Camaro over a race distance.
Braking appears to be where the actual downforce and aero balance numbers differed from the VCAT testing that initially determined there was parity.
Supercars CEO Shane Howard said: “Firstly, we would like to thank the homologation teams and D2H for their extensive work on this review.
“It required a considerable amount of man hours, expert analysis, and communication to work together to present these adjustments for approval.
“With these changes in place, Supercars is looking forward to racing at this weekend’s NTI Townsville 500.”
The top four drivers in the championship standings heading to north Queensland all drive Chevrolet machinery. Brodie Kostecki leads his Erebus Motorsport team-mate Will Brown by 59 points, with the Triple Eight duo of Broc Feeney and reigning champion Shane van Gisbergen, sitting third and fourth respectively.
The top Ford runner is Walkinshaw Andretti United's Chaz Mostert, who is 179 points back in fifth.
