Yep untill 1973, Bathurst was raced under "series Production" rules, which ment stock standard everything (in theory!)
Teams could balance and blueprint the motors, but that was all.
So stock gearbox, brakes, and interiors....just imagine 7 hours thrashing a ke10 round bathurst with drum brakes!
I know the trophy AMI got for winning class A in 1968 is at the museum!