Interesting.
I would think if the car meets the requirements for your class in Stock, and your dial in on the first round of the race is the class index , I couldn't see why it would not work.
Just make sure it has all the required mods ( i.e. driveshaft loop, helmet, etc.)
copy-n-paste from the rulebook:
DRIVELINE
Aluminum driveshaft prohibited except OEM. Carbon fiber
driveshaft prohibited. Driveline loop mandatory in all rear-wheeldrive
cars. See General Regulations 2:4.