Black screen - Sierra - iMac 12,2 - 560ti

Hi guys,

As per the title, I'm seeing a black screen on boot with a 12,2 system definition. I tried the AGPFix to no avail. Tried using the new web driver kext to no avail. I can boot when VESA drivers are used however. if i inject nvidia it causes a KP.

Any help greatly appreciated. This on my sandy bridge setup with the 560ti.