Originally Posted by glye

Not what you're asking, but I think it's easier, and cheaper, to use chainring spacers instead. Lighter too. These can be had in various thicknesses from 1 mm and up. If you need as much as 3 mm, you may also need longer chainring bolts. Another advantage is you get to keep your current Q-factor, which is good unless you prefer more widely spaced pedals.

https://duckduckgo.com/?q=chainring+...ages&ia=images