if your stock mounts are in perfect shape they will be pretty flush, if the stock mounts are a little warped, it may stick out a bit, but 3mm doesn't sound like a whole lot, as long as you can get the whole mount back in, it should be fine... be ready for a crapload of vibrations tho.. mine are on their way out(since my dash is rattling and now beginning to make birdy chirp chirp sounds)

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anyone want a cheap set?