if you include the brackets, it will fit her 98.
i jus put a 98 bumper on my 02. the brackets are a lil different, but mount to the frame horns the same.
one thing to note, however, i forgot to mention.
with a 01+ bumper on a 98-00 truck(with 98-00 lights/grille), you cannot access the screws for the turn signal housings. to change the turn signal bulbs, you need to loosen and lower the bumper each time.
you can see in this pic that the gap under the lights is larger than the gap under the grille. that is for access to the turn signal housing screws on a 98-00 truck.