Sorry, I didn't notice you were in Puerto Rico. I can't ship out of the country, too expensive for you and a huge hassle with customs and insurance if it goes missing. Try 4WheelParts.com maybe? And you can check the website for Daystar and see if you can find the kit that's for the Sport Tracs. It has some of the same bushings as the regular Explorer one, but less because the Tracs have less mounts. It might even be cheaper than the regular kit, I'm not sure.
Either way, the Daystar ones are a heck of a lot cheaper than OEM replacements.