OK then thanks, but the reason I chose the Ultra Kaze's were because of high airflow and more static pressure due to the 38mm thickness, I thought it would be better since I'll be cooling an overclocked Phenom 940 and an overclocked 4890
You can, common usage with peeps who have old fans. But a made to rad shroud is much nicer. Getting the fans about 1" away from the rad surface removes the dead spot of the fan motor. Been proven in temp tests. If your close to underad wattage issues, it can help. Not every WC rig needs to worry about this.