Something like this (except in a 1 inch version):

http://www.universalcycles.com/shopp...5&category=100

This locking headset spacer is meant for threadless applications. With a threadless headset, normally the stem does double duty by also keeping preload on the headset bearings. The locking spacer allows the stem to be changed and/or adjusted without losing the headset adjustment.

If you can find a 1 inch version of this spacer, you could convert to a threadless configuration while still using your quill stem.