Rick click on block then select edit block, delete your dimensions then re build.
Dimensions will not be shown.
The dimensions will remain intact with the blocks. Either you delete them (and apply fix constrain to the geometry if you like to freeze the size) before making the block or use Mark's method.
Thanks a lot!
can I put the dimensions on another layer like AutoCAD? I just need to switch this layer on or off to show or hide them.