You can do it without any problems!

But be careful, it depends on which version of the LL120 you have. It may be that the LL120s have a weaker static pressure than the fans supplied. There are 2 types of fans: Static pressure fans and airflow fans. The static pressure ones are specifically for the radiators, while the other ones are for the airflow in your case.

You can use the LL120 fans, but as I said, they may not have the same performance as the standard fans.