All is not lost.
If you perchance stripped the threads your pair of Shimano MTB shoes, you're in luck because you can come in from the top and swap out your cleat nut with this replacement SH-A200 Cleat Nut. For older shoes, this design replaces the old PD9051 plate and allows more forward and aft cleat adjustment.
B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.