Installation issue on HP ProLiant DL380G6

Hi guys, I'm having an issue installation on a HP server. The problem is VGA mode, that use 75Hz refresh rate and it's seems the displays I'm using works on 60Hz (I try to use several dispay models without succeed).

Is there a way to modify something in the installation media?

Could some modification un GRUB.CFG file help me?

The server is inside a Datacenter so I could not test random things, I need to go there with certainties.

Thanks!