85 chevy k 1500 bed replacement

[deanobigred]

question is what year bed can I put on this truck or on any chevy truck , what stops me from putting a say 2015 bed on it, bolt up , with ???

 

[Sprockmonster]

Long or short bed, stepside or fleetside. Need more details.
I'd say slim chance of getting a modern bed on there without a lot of modification, less the body lines being totally different and it being really expensive