i'm assuming you are referring to the freewheel, and spacing it to get a better chainline. if this is not what you mean, ignore this...

it's possible to move axle spacers from one side to the other in order to get a better chainline. the wheel will need to be redished, assuming it was aligned properly to begin with, if axle spacers are moved around.

and it is also possible to put a spacer over the threads before threading on the SS freewheel. there are more than enough threads there to do a proper job. harris cyclery sells these spacers.