not really... why u want to upgrade u have good build compared to most. anyway upgrade power supply unit to maybe 850? or 750? and if you can afford it obviously 4 more gigabites of ram and an i7. but i would change mother board? maybe get something newer sorry i dont know much as i buy mine pre built then swap things out only like graphics card.
GIGABYTE TECHNOLOGY Socket 1156 - Intel P55 - GA-P55-USB3 (rev. 2.0)