1984 Bronco II with build date of 1983

[p51mustangfox]

I have an 84 Bronco II with a build date of Sept. 1983. I am doing a CFI conversion on it from an 80s 3.8. In 1983 they were putting 17 gallon fuel tanks on them and mine has one. The 2.8 has a different diameter of locking ring compared to the 2.9 and I can't find a 17 gallon tank anywhere. I would like to keep it as original as possible, but the carb and a vacuum leak annoyed me to the point of doing a conversion on it (with some convincing from my father). So, I need to change the fuel system and I would like to keep the 17 gallon tank, but I can't even find a replacement for the 2.8 application. I am probably going to end up with a 23 gallon tank since that is what I am able to get a hold of. I was wondering if anyone had more information on the 17 gallon tanks?