It's probably teflon considering that's the only thing between two pieces of stainless steel and teflon works great for slick surfaces between things that would otherwise destroy themselves.
Well, I think if you didn't lower the ride height any and tried to simply move the mount outwards you would have found that the ears would be too tall or too short and you would have had to change them but if you "set" your ride height by putting your quad on a jack, you wouldn't have need math beyond the measurement you already had in your hand to figure out how high the mounts needed to be. It would have worked, not to say it would have been as simply as cutting them and moving them out an inch or so and rewelding them right back in place.