Dual Slot video card support in Dimension4700

I'm about to upgrade my PCIe video card to an ATI x850xt.  I was just curious if anyone knows if there's a problem fitting a dual-slot video card into a Dimension 4700 machine.  I noticed that plugging it into the PCIe port, it will also block the PCI port below it, which is fine, but other than that, just wondering if anyone had first-hand experience with any problems on the 4700 models doing this before I buy.  Thanks!