I have found the same to be true as well. No spillage at all. It is a well designed replacement cap.
Unfortunately, Navistar has told me each time I have talked to them that this replacement program will have an end, and that time is coming. The program has been running since 1980. I seem to recall that they mentioned either the end of 2004 or 2005 for the program. It apparently costs them a LOT of money to have this replacement program, (which is the result of a lawsuit from what I gather) and ending it would be pleasing to them.
Sooooo, as I have said before, even if you don't think you will need any, get as many serial numbers as you can, fire off the form and collect a few just in case!
For those who have not ordered - the form is on the server:
Navistar Replacement Gas Cap Form
For those purists who insist that the original is what they want, I would suggest that they get a new gasket from the CaseIH Dealer and then Reserve The Original For Shows only when the tractor is on static display. At all other times the new cap should be used
The last thing any of us on this forum want is to hear that someone has lost their Cub to a fire or that one of our Cubber Family has been injured from a gas fire which could have been prevented by using the new cap.
Soap box has been now removed