MC322LL/A is the order number for the 2,4 GHz late 2011 15" MBP. Original Mac OS X version is 10.7.2 (11C74). Usually, Macs cannot run older OS version than the one they shipped with (due to the drivers required), but there are some exceptions. I don't know if one applies here, but I doubt it given the CPU difference. Perhaps someone else can chime in.
