Clear up something in the original trans-am cars?

This is from the Mopar Performance book by Larry Atherton & Larry Schreib.
'Though designed as a pass car engine, the SB has made it's mark in racing with the 318 inch USAC Indy project, with the 305 inch Dan gurney Trans-Am racers, & with the current Petty Racing 355 inch Nascars motors.'