Hi, maybe these pictures will be helpful for somebody
my old Gigabyte K8NS-939 Ultra with Nijna :
1
2
3
my new Asus A8R32-MVP Deluxe with Ninja -
Compatible 
:
factory cooling chipset:
1
Thermaltake Extreme Spirit II
1
2
according to me more comfortable is to disassembly factory cooler assembly Ninja and assembly again chipset cooler