Hi all. I just bought an articulating wall mount for an opening that is 71" wide x 50" high. This opening should accommodate up to a 70" LED. (unfortunately, 75" is a tad too wide at 71 3/8") I don't have the tv yet so I plan on using my 42" in the space so I can have something to watch while waiting for prices to drop. However, I don't wish to have to redo the mount later on so I want to mount it now in the proper place for my new 70". Unfortunately, I can't simply screw in the mount in the dead center of the opening because I know that a lot of tv's (especially the larger ones) do not have mount holes centered; their holes are upwards-aligned towards the top. Can someone measure the distance from the top edge of the tv to the first mount hole? I've been trying to find a diagram online from a user manual but no manufacturer seems to publish this info anymore. I remember my Panasonic Plasma had specs every which way and was more detailed than an engineer's drafting.