Can a 55 Chevy 2 door wagon be shortened to use doors of a 4 door?

it would be cheaper to restore the 4 door But yes you can. you can make a hard top into a convertible -a 4 dr into a 2 door- a wagon into a sedan delivery

A 2 door wagon is worth a lot more than a 4 door wagon. Why would you want to chop up such a collectable car? If you prefer a 4 door you can sell the 2 door and buy a 4 door. Or you can trade someone a 2 door for a 4 door. But please dont chop up such a desirable car.

And to answer your original question, yes it can be done. It is a huge job. You need to cut out the "B" pillars, stretch the body, re locate the frame mounts, etc, etc, etc. Its a HUGE job!