can it be saved?

[Fab5]

Hi, new here to the forum(love it!) My question... I was giv'in a 87 4x4 short box. Didn't know how bad it was until I took off the bed to see why it sagged to one side(drivers). Besides the rot, the frame is cracked from the bottom of the main rail all the way to the top. It measures almost an 1/8" opening from the bottom, closing about 3" up from the bottom of the frame.
The only thing holding on is about a 1/2" of the frame(what the bed sits on).
This "crack" is right behind the gas tank. The truck runs and drives great.
Can this be fixed? If so, what do need, and where do I start? Or is this just a waste? Thank you for any help.