Since Chevrolet did not make a pickup bed for 1930. You can make anything you want for a body. Many independent body builders did make a pickup box for the Chevrolet Chassis such as Martin-Perry, Hercules, Cantrell, Mifflinburg Body Co. just to name a few. No One that I am aware of makes a kit for your truck. Try to find some pictures of a pickup box from one of the body builders and copy it or just make your own as many buyers did in those days. I have some pictures of a telephone truck that the body would probably be easy to make.
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34 & 35 trucks are the greatest. 36 high cabs are OK too.