buy a shortbed frame-$500
buy a short bed-$500 if your lucky,
drive shaft,
fuel lines have to be altered, im sure there are other smaller things to be done
Just shorten the frame and the driveshaft and you should be all set. When I lengthened my driveshaft it cost about $150 bucks with new U-Joints and resleeved so it should prolly cost around there to get the driveshaft shortened. You may be able to keep the stock gas tank in the stock location too.