these heads actually made in australia?

I actually have another set of the speedmaster heads in use...or ready to use...but our race track...the STrip...closes for 3 months in the summer...so i can not get the car back out there and I have flow bench info on them...bought bare...local machine shop did the valve job ....It made one good pass and then the guys borrowing the car decided to work on it...went from 11.60s to 12.20s in one weekend.....and that 75 Duster is not lite...and neither was the driver...lol