Quoted:
I bought a AR15 with a A2 fixed front sight tower. I think the Leupold mark 2 IMS scope mount can get my leupold 2-7 power scope high enough to clear the front sight, am I right?
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That mount will give you an absolute cowitness height. The front sight will be a blur or shadow at 2x and disappear at 3x and higher, as the scope cannot focus that close. It will see through the front sight as if it is not there.
I don't think there are any, certainly very few, one piece mounts intended to be high enough to "clear" the A2 front sight. Going that high will destroy you cheekweld making you raise your head up off of the stock.
The Mark 2 IMS is the same height as virtually all other one piece mounts, about 1.5" from centerline of the rings to the top of the rail.