This seems to be the motherboard you have. The only thing i can suggest would be to use right angle sata cables and move the sata cables directly around the graphics card if it will work. Other than that you will need a new mobo most DELL motherboards aren't built like mobo's you buy just off newegg so any mobo you buy such as http://www.newegg.com/Product/Produc...82E16813131604
. Most of these ones off newegg arent made like the garbage that dell provides so you will have a ton of room to install a big graphics card on the mobo.