Dan at Hemmings Blog did an article in 2010:
I’m not sure anybody has a straight story on how many Tirebirds were built by Jerry Titus and Terry Godsall to promote and race on the new B.F.Goodrich radials in 1970. Add in the fact that Goodrich wanted Titus to build several replicas for further promotional purposes
This was the third of three cars built by TG Racing for the 1970 Trans Am season. Titus’ partner Terry Godsall secured BF Goodrich sponsorship for the team at the end of the 1970 season. The team convinced the SCCA to allow this car to run with a Chevy engine instead of the problematic Pontiac engine base on the fact that Canadian Firebirds were delivered with Chevy engines.
This car was entered in the 1971 Daytona 24 hours as a Firebird and then was converted to Camaro body work in time for Sebring.
https://blog.hemmings.com/index.php/2010/05/21/hemmings-find-of-the-day-1970-pontiac-firebird-tirebird/