Ford Performance has been lobbying for the change since before the Australian Grand Prix, based on concerns that the Ford unit is at a disparity to the Chevrolet V8.
Those concerns have centred on throttle response with the alleged performance disadvantage most notable from fourth gear onwards, according to a number of Ford drivers.
Supercars is now set to give the green light for the mapping change, which will be applied to the 11 Mustangs in the field for this weekend's Perth SuperSprint.
The mapping change is thought to relate to throttle response and low-down engine response.
This is one of two parity adjustments in place for Perth this weekend following a Centre of Gravity change mandated for the Camaros.
The Chevs have been required to redistribute just under five kilograms of weight to above the fuel cell to raise the Centre of Gravity by 2.3 millimetres.
All cars in the field will also run a revised catch can breathing system in response to the engine fires that scorched Nick Percat and James Courtney's cars at Albert Park.
The breathing will now be directed towards the back of the car rather than directly into the engine bay, as was the case until the AGP.
Teams have also been allowed to add extra gusseting to the chassis clips to improve the repairability.
