CB750J Master Cylinder

[muser3]

Hello Friends,
This is my first visit to the forum and I come  in search of information.  My 1977 GL1000 has a non-stock Master cylinder which has been identified as one from a 1976 CB750J.  Can anyone confirm that the piston size in that MC is 14mm or very close to it?   I need to rebuild the MC and the piston size will confirm the model kit I order.
Thanks very much and if you ever wander over to the nakedgoldwings, BMWRS, or BMWMOA forums please look me up.  
muser3 aka Lee
from the piny woods of East (friggin' soggy) Texas
[e-mail]