long bed to short bed

I would love to have a shortbed crewcab 88-98 CK truck. i been lookin on autotrader and such and finding 92, 93, 94 longbed crewcabs for reasonably cheap so im wondering what kind of frame mods would need to be done to make it a shortbed. dont really want to build a whole new frame if i dont have to. pics would be AWESOME too!