hi, most likely the dealership's part's department.
unless you up-grade it to the hellwig front sway bar.
than you will recieve all new washer's, bushing's,
even the big middle rubber, that mounts the bar.
not just the end link's.
i belive your's it like all oem. approx. 3/4" bar.
the hellwig is 1", which accroding to DAVE at hellwig,
it will give you 30% better handling.
and since i have both front & rear,
i can tell you it's a dream to drive.
i would go to suspension section.
and look there for what you want.
it might have the info.
I believe the sway bar diameter is stamped right into the side of the bushings. It is in metric. You should see something like "24" stamped onto the side of the bushings. This is only if you want to crawl under your truck with a flashlight. Like Gorilla said, call the dealer, they can confirm.