TRK,

If guide wear is minimal, a special tool is run through the guide. The tool knurls, or raises a furrow through the ID of the guide which is then reamed to the exact size of the stem.

This procedure repairs the worn guide without the expense of sleeving or guide replacement ($$$). The 'furrows' allow oil to lubricate this stem/guide area better too.

Some folks look at this as only a temporary fix, but many automotive machine shops routinely do it...I had it done on my engine and it worked out perfectly.

I am just tossing out options to bushing or replacing your worn guides. Talk to your automotive machines about knurling.

Stuart.