I edited this post.. the part I linked to was not the right part..
your van is a 86 e250 w/351 correct? i was trying to find your sending unit for the rear tank.. 22gal?
With only one line that connects to the sending unit?
You have a carb so it wouldn't have a electric fuel pump

 

That's exactly the problem I've been having, all the sending units that I've found available have been for the EFI/TBI systems with the in-tank fuel pumps. I could make it work, which is most likely what I'll be forced to do. Fortunately, AutoZone has both the sending unit and the connector, so I MIGHT be able to pull the wires out of the original sending unit connector to put it in the new one to fit the new sending unit.

 

Here's what I am thinking...
My 1985 e150 uses a spectra F15B tank
Your 86 calls for a F15c

F15B
22 Gallon; Behind Rear Axle; 33-5/8 In. x 23-1/2 In. x 11-1/4 In.

F15C
22 Gallon; Behind Rear Axle; 33-1/2 In. x 23-1/2 In. x 11-1/8 In

I think either tank would fit.... BUT... There is a difference in the size of the hole where the sending unit goes in... the sending unit with a pump requires a larger hole... Perhaps your tank is a F15B and would work with a 85 sending unit?

You have access to measure the sending unit hole diameter. I would measure it and see which one you have.. I still have my old tank and could measure the hole in mine and we could compare the two... If yours has the smaller hole, then you would use the 85 sending unit that has no electric pump!


Also see if you can read the part number on the sending unit. you have the tank, rubber O ring, sending unit, and then lock ring. the part number should be on the face of the sending unit just inside the lock ring..
The 85 part number is EOUZ9275B, the older number is D7UZ9275B