Originally Posted by Little Darwin

There are plenty of threads on this topic...

To sum it up, few peope object to adding modern parts, many prefer that you keep the old parts in case you want to restore it to a period correct state.

I have a vintage bike where nothing but the frame and seat post are vintage... oh, and the cantilever brakes too.

My opinion is that if it makes you want to ride it more, then it absolutely belongs on your bike.