hey dude, hows your day treatin ya? im quite certain that all model commodores VN and upwards are fitted with power steering including the horribly basic executive that came out with a front bench seat and column auto, yuk!
i changed the steering rack in my 73 HQ with power steer and it went in like magic, job worth doing as she felt like a brand new car.
score yourself a workshop manual too if your gonna be tinkering. ellery brand is heaps better than the clymer, i bought mine on ebay mate.