Don’t forget the whistle hole.

I also got rid of my wolf air oil separator, not a good concept returning to the engine what the engine wants to barf out.

I just used some lite aluminum tubin with a high heat resistance hose.

Robert:

Please pm me with some contact details and I’ll see what I can measure on my 250. Have to be a bit careful though as these aircraft are getting old – there is no guarantee that mine is an exemplar of the type, for example. Having an aircraft mechanic fabricate what is needful is likely the right way to go. What did you find in the parts book?

William