If it's a factory-installed sight, you might try contacting STI for more info -- and they may have options for you, or can certainly give you specs. You might also talk with the people who make the new unit you want to install, and ask them.
(I've heard of Bomar cuts -- and there's more than one of those -- but I had not previously heard of an LPA cut. I've had LPA sights on several different guns, all of them factory stock, with different dovetails.)