That is an excellent question, and the answer is I have no idea. Perhaps I could check it if I have to drop the tank to fix the leaking grommet issue anyway.
That would be a good idea. Every aftermarket sending unit I've seen doesn't reach the bottom of the tank. With the tank out you can look through the filler neck hole and tweak it accordingly.
Just to expand a bit more than on the thread I linked you, it sounds like you will need to bend the float arm down a bit too. That way it reads the full range of travel. I've had to bend the arm down a bit on each aftermarket sending unit I've dealt with.
At that point you can either "get used to" the way your fuel gauge reads, or get a Meter Match.
As far as the grommet if you need a new one I pointed out a good quality new one to the guy in this thread: Fuel Filler Neck Grommet Replacement
