I seem to remember a discussion about this a while back and the tube length was given. mine measures 6" outside of the casting, you would add the depth of the counter bore to that. You can use one of those 3/8" made up brake lines from you FLAPS for the tube.
Then to calibrate the dip stick just simply add four quarts and mark it one quart low, then add that last quart and mark it full.

DG


Denny G
Sandwich, IL