no, not "stepside only" one from any 81-87 short bed should work for you, , the "stepside only" parts would be the filler neck which you should have. SOME long beds had the same tank while other long beds had a 30 gallon tank.
the one I have came from an 84 short bed I saw the truck it came from.
I guess if I had the cross member from the 84 with the straps (which the damn junkyards always cut) and swapped it from the one in the 80 that this tank I have would work in the 80 from what I have seen. what is the tank you have? do you know what it came from? from what I have checked out, I need one from a 79 or an 80 "only" to fit exactly without taking a cross member from an 81-87, to make this tank work in the 80. I wish I had access to the factory parts book I used to have free rein of....
I hope this isnt thought of as "bad" here but in the "trucks" section of "Moparts" I had a thread where I asked the difference between the tanks. I saw a pic someone else posted in that thread with the 2 side by side, and from that, I didnt see anything preventing the 84 tank from going in the 80 but by the rear most strap I guess that the 84 tank is squared off where the one he needs is "45'd off".... (going by what my kid has told me, when he tried to put the 84 tank in the 80)
Around here I see a decent number of 81+ Dodge trucks in the boneyards, so yours should be more available.... not so 80 and older in my area.
The sending units are different too,,,, but wired up the same, either should work the gauge properly in either truck.
I still have the junkyard reciept from this 84 tank, they charged me $80 for it..... ID trade someone straight up for the right tank I need.... I need to look up your town and see how far. I am gonna be in Ohio in Aug., I really want this truck operational before then...... if all else fails we could swap then. Im gonna be in the Sandusky-Norwalk area when I go.
I live 1 hr south of Chicago. If you had what I need maybe we could meet up somewhere within Indiana and trade? just a thought.... I have 2 possibilities closer to me that I am checking on closer to here, to see if I can find something. I was all over southern IL (had a wake to go to) plus Cape Girardeau MO and Paducah KY last week and saw so many random backyards with 10+ Chevy POS' each, sprawled about. I did see some 80s Dodges in the yards I was in.....
this 80 is my son's, I have an 85 long bed D150 myself, that I am working on. found mine sitting, had been for many years before it was mine. so lots of repairs related to that. lots of "previous owner interference" on the wiring harness, that + a completely clogged cat were the 2 biggest issues with it when I got it. unsure what direction I want to go with mine, have several ideas.
my son overpaid for his out of Mississippi via Ebay, both are currently slant 6 equipped.