While not an official SCCA Trans Am race, a Yenko Corvair Stinger did run in Les 4 Heures du Circuit Le Circuit Mont-Tremblant. This was a four hour race for Trans Am type cars held on May 21, 1967 at Circuit Mont-Tremblant, Mont-Tremblant, Québec, Canada. According to the race results clipping, originally posted by Jon Mello in the 1967 season review thread, Donna Mae Mimms was the driver. The car did not finish the race, stopping on lap 18 due to ignition and clutch failure.
You can see the rear end and the striped roof of the white Stinger parked behind the Camaro in the first picture.
The front end of the Stinger can be seen at the top of the second picture above the roof of the Mustang.
The front end of the Stinger can also be seen to the upper right in the third picture above the hood of the Falcon.
The pictures can be seen here: http://www.autocourse.ca/photos/saison1967/transam/transam/transam.html