I would do some research to make sure. Intel develops their CPU's and chipsets in what is called a Tick -Tock cycle. They introduce a new CPU architecture, one that usually requires a new 'form factor' - a certain CPU slot type (e.g. 775, 1155, 1156, 2011, etc.). Then they refine the CPU architecture (the 'tock' cycle), which usually means they manufacture a new line of CPU's that have the same form factor, but have a smaller transistor size (and usually a few new technologies and/or enhancements, like faster HD graphics, new instruction sets, etc.). Here is a list of processors in the same family as your current one: http://ark.intel.com/products/codename/29902/Ivy-Bridge
For any CPU - motherboard compatibility, there are 3 questions to be answered:
1) Is the form factor (slot) the same?
2) Does the motherboard support the new 'tock' enhancements (this often requires a BIOS update).
3) Can the computer handle the new CPU? (This is usually a question for laptops and power requirements and is of lesser concern for Desktops, though the operating system has to be able to work with the new CPU - but Windows 7, 8 and Server 2007 or 2012 should handle any current Intel CPU offering).
So the main question you have to find out is if your motherboard supports the CPU you are considering as a replacement.
Actually, I just looked at the Intel CPU chart for your processor and the i7-3770K, and they have the same architecture. In fact, they have all the same specs, except that the i7-3770K has faster speed and built in graphics as well as hyper threading, and the i5-3330 has an I/O virtualization feature that the i7 does not. I doubt you will miss the second feature of your current processor, but it is worth researching.
They are both Ivy Bridge processors, so if the i5-3330 works in your system, the i7-3770K will work. The i7-3770K is a great processor. You also might consider the i5-3750K if you are on a budget. It is a 4 core processor with all the same features and speed as the i7 except for hyper threading, and it costs around $100 less. Some programs will benefit from hyper threading, though a good many do not. Again, research. Start with the question: 'What do you mainly use your computer for?' and go from there (i.e. if you do a lot of video editing, see if your editing program benefits from hyper threading; if not, maybe the less expensive -5-3750K will suit you just fine)..
Sorry, not much I can do to help.. I went to support.dell.com/manuals and looked up your computer, but for some reason my iPad and computer display the specs PDF as a blank page. I can view the non-relevant PDFs fine, but the one I need to see to help you is out of my reach. I tried to find it somewhere else to no avail. If you can get me a readable copy, I can solve that for you. Otherwise I have to go by hearsay, which was that the i7-2600k was compatible, but no info on the i7-3770k. BE AWARE!! That was a response to a post for the same PC looking to upgrade their CPU and can not confirm validity!!