I recently dropped the gas tanks out of my car and re-installed.I'm not sure how to install the fuel filler and connect to the small hose that goes on the back side.These are the chrome fillers and hhave a small nipple on the back to install hose.

 

Re-connecting those little vent tubes onto the fuel filler assembly is an absolute pain ! It helps to have an assistant, and to also wiggle the filler assembly sideways whilst you "persuade" the vent tube to go onto its nipple. Whatever you do, don't let the tub disappear back into the wing void as it is very hard to get it back out. How do I know, Yes you've guessed it !!

Doug Dwyer may have the answer. I did my car in around 1989.