[belbono]

I got my problem under control:

For the Gigabyte GA-965P-DS3 (revision 3.3) with the Syche Mine (rev B) you will need the retention kit (SCURK01).

You can even mount an alternate northbridge cooler like the Coolermaster Blue Ice II.
In this case it will be very narrow, but I can assure it will be ok.