Nah you dont need to replace it you need to sell me your bronco as it will never run right again. Lol Thats a nice bronco.
If we knew where you were located you might have someone close by that has the part your in need of.
Have you called pony carburetors?
do you have a working phone number for them? the ones on the site are down....
http://www.ponycarburetors.com/
Number should be working. They also sell frequestly on ebay. Maybe try contacting via email.
Good Luck!
BTW Nice Bronco!