Your GA-Z68MA-D2H-B3 has 4 240pin so you have 4 memory slot. A set of Corsair Vengeance comes with TALL heat spreaders. You should install the memory first before installing the heatsink. Some people installed in the first slot without any problem but the heat spreader will be close to the Hyper 212+. Don't think you will have any problems though. If anything, you can use the other RAM slots.