Had these installed on my 2006 Martin HD-28. Much better look and stability than the stock tuners (a closed back Gotoh but Martin branded). The included bushing fit the factory holes with no modification needed, but did require new holes for the mounting screws. I love them!
I replaced the original tuners on a new Eastman E1D with these. Everything aligned with the original holes but you will need to add a shallow counterbore for these to set flat on the headstock. Easy install and a big improvement.