For common 1" threaded headsets about 1" of threads is enough for the threaded parts to fit and for the bearings ability to be adjusted. Not a hard number, just what often is the case. It's easy to measure how much threads your specific bike/headset needs. It's this number that you should know and be working with when sourcing a fork. The first choice is setting dimensions to duplicate is to measure the actual parts already in use. Anything else brings the danger of false assumptions to the party. Like what does a listing mean by "A" when they don't define "A".

This next is an example of what dimensions you need to heed (dependent on what you call a headtube length)- HT + HS stack - 1 or 2mm = steerer length (crown seat to top of threads). 130 + 39 (classic Campy HS height BUT not your HS stack?) - 2 = 167mm steerer. The above fork you describe is then 240 - 167 = 73mm of un needed length. 130mm thread - 73mm un needed length = 57mm of remaining thread. This will work but note my earlier warning about having the steerer's threading overlap with the stem's wedge location, for safety the threads need to end above the stem's wedge. So how deep into the steerer will your stem be? Note again these numbers are either taken from your posts or are approximates of your real ones. Andy