I've received bad mounts before. The locator nub or 'teet' was located in the wrong clock position. This was either a manufacturing or packaging mistake. I got them reshipped and they were correct on the 2nd go.

IIRC correctly, either 3.0 or 2.6 the mounts are identical L & R.

Not sure if this is your problem or not, but it happens alot with mis packaged parts. Also happened to me once with a caliper for the Montero. Correct caliper, but had wrong mount bracket.

Jim