Last year I put an adjustable vacuum modulator on my ****** an now I can't remember if I turned it any,or if I did how much. --getting old and should write these things down,but then I lose the notes LOL. Anyway is there a way to find the original position? like can you turn it all the way in or out and then count turns till its where it was originally?
If you are happy when the part throttle shifts happen then you are good. If not in for later shifts, out for earlier. To answer your question start in the middle but I am not aware of any exact setting. Good luck!
I'd just make a test run with it as is, & go from there if any change is desired. No way to know where the factory set the starting point.