Last saturday my dad and i fixed my fuel sending unit. All we had to do was take the bottom retaining piece and the can that goes around the float off and pull the float off the sending unit/pick up. It turned out the float was swollen and became tight on the pick up tube. So i filed on the inside of the float while my dad smoothed out the pick up tube and we put it back together and it works great. I will suggest that you pull the bottom retaining piece off first then the can, we pulled the can off first because we werent sure how to get in there and now its out of round and touches the float so its not on right now. Hope this will help someone from having to buy a new sending unit. sorry i didnt take any pictures.

this was on my 68 delta, idk what other years used that style sending unit.