By lopsided I assume you mean angled left or right? We had the Geek Squad install our 48" Sony (a little smaller than your 75) on the wall with the same Sanus mount. One of the instructions after they mounted the tv to the wall was... as you move the unit in and out and left to right...sometimes the tv angle goes a little off level...we have seen this a few times when we return the tv to a flat position to the wall......the reason he gave us for this happening was because it is a floating mount. He told us to very carefully, with the flat palms of our hands , hold the sides of the tv and rotate the tv to level. Easier on a 48 than a 75. Ours has never been more than a degree or two off level. This works for our tv, but not sure it would for your larger set? Best bet is still to ask the experts (Geek Squad) back at Best Buy.