cant help with the QLD laws but heres the nsw ones, they probably arent much different, and if anything QLD's ones will be more relaxed. basically if you have a read youll find the maximum angine sixe in cubic inches is total car weight x 0.294
therefore a coroner weighs about 1.5 tons? (there about the same as a bluebird?)441 cubic inches?? thats in nsw.