To a non-Dell board that would let you add a graphics card?
It depends on a few things. Which processor do you have? Assuming a Xeon 34xx, that severely limits your options. For example, on Newegg.com, this is your only choice:
www.newegg.com/.../Product.aspx
However, it won't take an x16 graphics card either.
If it is any other processor, I'm not sure that "The spec is soo good" is quite accurate :)
When looking for another motherboard, you will need to get one that supports the type of ECC memory that you have (Registered or Unregistered/Unbuffered - not all support both), and has a chipset that supports the processor. You will also need to inspect your T310's power supply for a "standard" connector and make sure there is a place/way to connect the control panel.
I think it would be more worthwhile to try to find a graphics card that will work than to replace the motherboard ... but that's just me.