Flashing 7950

Hey guys, I own a mac pro 1.1 and want to put a gigabite 7950 in it.

I realise I need to be on 10.8.3 or higher in order to get the drivers, but aparently I need to flash it with the mac edition EFI in order to get boot screens.

I will be using the charmelion method in order to get 10.8.3 on it.

Will I even need to flash it if charmelion suports the 7950? (Im bootcamped with win7)

Does anyone know where I can find a guide to flash the 7950?

Thanks
tom