Shortening a bed

Has any one ever shortened a long wheel base bed. I want to put a short wheel base fleetside bed on my truck and can get a long whell base one. would it be possible just to slice like a foot and a half out of the front of it??? its on a 75 chevy, the beds are the same from 73-87 i just cant find a short bed anywhere so i figured id make one. anyone ever done this???

thanks