are all vy rear calipers the same? thinkn of replacing mine.... has constant brake squeel coming from the rear (which one im not sure). have replaced rotors and pads. thinkn of changing calipers.
Have you checked the hand brake shoes? On early models they move out of position and rub on the inside of the rotor. There was a modification to stop this essentially a bracket and spring for each side. This is available as a kit from Holden, if the original hand brake shoes are in it you just need to drill a hole to take the spring or you can buy new shoes. You can take the rotor off to check if you have this spring and bracket.
As far as I know the calipers and rotors are all the same unless it is a HSV or something like that.