i remember i ordered in ma work place. i rang 2 repco and asked them whether they had r33 na rotors in stock which they couldnt find. so, they asked me to measure the size of the rotors which i cant remember now. try to measure it the thickest of the rotor and the size. also look back of the rotors there should be a mark of the lowest thickest.
Hope thats help u.
Good Luck
Mick