My Hyper 212+ fits very snugly against the RAM. Doesn't push against it, but the bottom edge of the 120mm fan is flush against the heat spreader.
Unless your memory slots are abnormally close to the socket, you should be fine. If you're not using a pair of fans, you can always just move the fan to the other side to be sure it will clear. You can remove the fan mounting brackets and flip the fan around so it still vents out the back of the case. Takes about 2 minutes with a screwdriver.
The fans detach from the Hyper 212 via plastic clips. Move the fan up the heat sink about 3-5mm should give you about 1mm of space between the bottom of the fan and the ram. I have heard of people using vengance RAM with the 212 just fine. You will have to play with it. You can even get to the ram easily by simply uncliping the fan.