clutch fans move alot more air then most thermo's EVER will, you can buy new centres from any good parts store, they may even recomend a kit, you drill the hub poor the fluid out, fill it with the new fluid provided in the kit, then you put a plug in it

i know Falcon thermo fans work well on dirty nissans, but there rads are a bit wider, but AU thermo fans work AWESOME!!!!!!! you throw a empty bottle of coke in front of my mates car it sucks it into intercooler