How hard is it to change a long bed into a short bed if possible

Electrical system, un connect your battery then reconnect

that will tell you if all the truck is of one body or if the bed doesn't match the cab for example if wrecked they may have had to replace bed of truck so that would have a different vin #

1996 Dodge Ram 3500 diesel Standard Payload, lbs.ext. cab long bed 5151, ext. cab short bed 3915, reg. cab long bed 5340, reg. cab short bed 2372.---------------------------------------------------------------------------------------
Multi-Di@g Access J2534

No I don't believe it will as the frame/ wheel base is different. to check measure from the front of the bed to the bolts in the bed. This will let you know.

SHORT BED TANK SIZE 26 GALLONS LONG BED TANK SIZE 34 GALLONS.

Removing the bed is in no way easier than just dropping the fuel tank, and the fuel tank was designed to easily be dropped down from the vehicle. Who ever told you that removing the bed was the easier way is certainly not an auto technician or even a mechanic.

The entire bed line will need to be removed. The long screws that hold the metal bracet where the bed extender attaches also hold the tail light assembly in place.
I pulled the bed liner up at a 45 degree angle and layed it on top of the cab. This revealed the screws. Take both screws out and lay to the side along with the metal bracket for the bed extender.
Now firmly grab the edges of the tail light assembly and pull...there are 2 hard rubber nipples that snap in to hold the assembly. You will feel like you might break it but you won't..just pull straight back hard. The assembly will "POP" out and then you can just twist the back of each bulb there are (3) and pull out..now you will see the bulbs..just pull the bad bulb straight out and push the new one into place. Now just reassemble. Total time will be 30-45 min. for this repair.

body lift would be cheapest and not real hard to do.ranch makes a nice suspension lift for that truck but alot more money and will need allignment and possible proffetional to install properly.remember you may need to change your rims depending on lift.

take the six bed bolt loose and then take three buddies slide the bed back put in the new pump slide it back n place and put the bed bolts back in. if u drop the tank u can easily break the hard plastis lines that go to the fuel tank. u only have to take the fill lines and taillight wires loose this way its alot quicker, and easier.

You need to remove the fuel filler tube, disconnet the harnesses that hook to the taillamps, the license plate lamps and any other wiring. Spray penetrating oil around the bed bolts before you remove them. Undo the bolts & have people help you lift the bed off. Not a "hard" job, but a rather heavy type of job. I commonly pull the beds whenever I am changing the fuel tank sending unit.