Are there any limitations in the setup of using the 111LT-360CB chassis with a Dual Xeon motherboard (such as the X8DTL series motherboard) together with two pieces of the Xeon 56xx CPU?
The SC111LT-360CB can support some X8 DP motherboards but it definitely has restrictions.
In your case, I suggest additional cooling. A fan tray and fans can be added at the left-hand side of the chassis for better cooling to prevent the IOH from overheating. The parts you need are MCP-320-11101-0N, which is the fan tray, and two 40x28mm fan options, FAN-0106L4 or FAN-0065L4. Furthermore, only CPUs that have a maximum of 80 watt TDP can be used.