Could it be an option to open up the bottom fan holes to get a maximum of air flow? Just cutting out 2 120mm holes with a basic fan grill will get more and and maybe less noise (got a similar grill on my LL pc v-351 and I see al ot of people who are cutting them out because of the noise and flow.)

It's just an suggestion and don't take just my word for it but it looks like it could kill the airflow to the radiator.