Rock Auto has three different types of fuel senders for the 85... One of them looks like it is for a carburated 5.0 (the one with the long arm).
Then there is one with a short arm, which I presume is the right one for my car (it is the early 85 with the external pump).
Then there is one with a fuel pump hanger ...
The part numbers are SUFM0[7,8,9], with a Dorman with the fuel pump hanger.
The fuel guage seems to only work with the top 1/2 of the tank. 3/4 on the guage is full, and empty is a little less than half full.