Hello Buddtx,
Thank you for replying. As I have mentioned that the Optiplex 790 has a Intel Q65 Express Chipset and was tested and shipped with Intel Core i7 2600 / 3.40GHz and Intel Core i7 2600S / 2.80GHz.
However, looking at the specification of the Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000, and comparing it with Intel Core i7-2700K Sandy Bridge 3.5GHz, I would like to inform you that, it should be compatible with the system.