There is a pedders in wagga. Most pedders suspension have their own access for lowering springs properly. They can add or remove springs to suit whatever your needs are. You can send them your springs or take the whole car. It is better if they do the whole job so there is no mistakes. They also supply longer U bolts and from memory they also custom make u bolts.
I drove around for ages (about 2 years or more) with a flipped spring. It is just luck of the draw if you break a leaf. It soes put a lot of pressure on the other springs. I just reversed mine because with the kids in the back of the 120Y it's a bit hairy. Piss funny though over speed humps.