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/
And then I learned in Sept 2018, that they made 6 promotional cars!
a BFG contract and a magazine ad campaign. Part of the contract was for T/G Racing to build six BFG “Tire Bird” show cars, a play on the Firebird’s name. They would be purchased new from Royal Pontiac in Los Angeles and modified in the T/G shop in Tarzana, California.
With most of 1970 production finished, BFG started with 1971 models. The six Trans Ams were built to look like T/G’s Trans-Am race car, featuring the special blue and white paint scheme and “92” on the doors and hood. But they were strictly for show. Though T/G stripped the Pontiacs of their stock interiors and insulation and installed one race seat and a fire extinguisher, their “rollcages” were made from exhaust pipes. The “fuel cell” in the trunk was a mock cover.
Each promo Trans Am was equipped with an H.O. 455 big-block backed by an M21 four-speed transmission. BFG Radial T/A tires mounted on magnesium Minilite wheels were common to both the race car and the show car, as were hoodpins and rear-window bracing.
BFG distributed the six promo models to tire stores around the country to put on display and draw attention to the new Radial T/A. When the racing program ended after the 1971 season, BFG sold off the promo cars.
Tom Senter bought this particular California promo Tire Bird from BFGoodrich when he was editor of Popular Hot Rodding magazine in Los Angeles in 1972. Johnson says, “They gave him a crate that had the original interior parts. He took all the interior out—the racing stuff—and put the regular interior back in, and made a street car out of it.”
The H.O. 455, still in the engine bay, had already been burned up when somebody in the shop drove the car with no engine oil. Senter sold the H.O. 455 for $300 and used his contacts at Pontiac to try to acquire one of the new Super Duty 455s. This was late 1972, and the 455 SD was not available.
Senter contacted friends at Berger Chevrolet in Michigan to buy (for $750!) a Chevrolet LS6 454 with 11.25:1 compression. He documented the build in PHR as he transformed the car into a high-speed road racer. True to his hot rod background, Senter removed the graphics and painted the dark blue body Ferrari Fly Yellow.