For most iron models, Mizuno offer lighter weight heads which can be used to keep the swingweight to a standard balance for club lengths up to +1/2″ longer. Anything longer than that and the swingweight will increase above the recommended balance. (As a rough calculation, every extra 1/2″ in length will increase the swingweight by 3 balance points).
Irons can be built from 1″ shorter than standard up to a maximum of 1.5″ longer than standard.
Woods can be built +/- 1″ from standard length but the swingweight will increase by 3 points for every +1/2″ and reduce by 3 points for every -1/2″.