virtually any 40 gallon fuel tank from that bodystyle will fit. The only thing to note is that there is/was 2 different styles of tanks, however, I'm no sure a 40 was produced in both styles.The first one is the center mounted tank, which is pretty squarish. The other is an offset side tank, which is rectangular shaped. I think all the suburbans with 40 gallon tanks of that bodystyle wer the center sqaurish ones, but I could be wrong. Hope this helps some...