Thanks all for the input and offers to loan/rent the tools. I own several diesels and these are tools that I would like to add to my toolbox permanently. I think I have a bad prechamber in one of my cars (misses on one cylinder when cold but runs great when at operating temperature) and have decided to buy/make tools rather than use the old hammer and punch on the ring as I did before when one went bad. Made a crude prechamber puller back then too, but it really never fit well and really messes up the prechamber threads if you are trying to reuse the chamber. Since I am a cheapskate, won't use them all the time, and have access to a machine shop and materials, I should be able to make them for a lot less then those tool places want. Just need the thread sizes so I can buy whatever dies I need (which is still a lot less then buying the tools).