What special or particular machining tools are required to O-ring/Fire ring a head? Can any machine shop do it or do you have to take it to a special shop. Reason I ask is because I work with a very talented machinist and we have quite a few tools here to use but not sure if we have everything. I know that to get it done properly I should take it someplace that has experience but I am still curious what all is involved with doing the job. Thanks.

 

The thread I started on O-rings. Did them myself on my Bridgeport with a boring head setup, mine happens to be a D'Andrea boring head. Pictures in there too.
https://www.dieseltruckresource.com/...d.php?t=169122