My kid has an 80, D100 stepside. /6, A833OD. Pretty clean, he (overpaid) via EPay out of Mississippi. but one issue with it, is that its gas tank has a split in it, the PO put some kind of tar like goo on it to "get it down the road". The problem showed up just before the kid parked it for the Illinois road salt season, he started seeing a "drip" on the driveway.
Anyways we have been looking for a gas tank for it since. this one has the longways tank, between frame and driveshaft. The only tank I have found within a sorta reasonable distance, from a 72-80 has been modified, someone modified it and put an aftermarket float/sender into it so I passed. Ive been able to find a few for (as the interchange at the junkyard says) '81-87 D/W series.

2 different optional capacities aside (in the 81+ trucks), a 20 and a 30 gallon, what is the difference between the "correct" tank for the '80 vs the '81-up? Is (are) the difference(s) enough to keep me from putting the '81-87 tank into the '80 frame? Filler neck location within tank, ohm differences in sender throwing the factory gauge off, shape/size of the straps,etc? If there was an ohm difference in the sender, would the original sender from the '80 fit right, in the newer tank?