Most are made from Ash, start with nice dry straight lumber. Buy the best tools you will need for the job.
I show the process I used to make the wood in this pickup. it is not a Dodge but should be similar. https://www.jalopyjournal.com/forum/threads/fixing-a-smashed-31-model-a-pickup-cab.1143362/
I remember seeing a tudor Deuce sedan that used old hockey sticks in the hole in the roof and I have collected a few to use in my Austin.
We can offer suggestions for making metal bows for a touring car or roadster. And we can offer suggestions for making wood bows for a closed car such as a coupe or sedan. but you're only going to need one of these types of suggestions. How about some more info? and some pictures of the car as it sits
I wanted to put a suspended headliner in my '40 pickup instead of the cardboard pieces that Ford used. That meant making 3 roof bows. I cut a 2x6 on the bandsaw to the shape I wanted and then cut/planed some clear ash into 1/8" strips. I glued and laminated them onto the the 2x6 mold with lots of clamps. After a couple days, I removed the bow from the mold and there was no springback. Turned out excellent.
Many. early tops use a combination of metal top irons with wood top bows , the old way of making the wood bows was to use steam bent ash , others have accomplished the same thing by laminating thin strips of wood on a form . Former H.A.M.B. member ( now deceased) Langy from England did a nice write up some years back of his SS top irons with steam bent wood bows , I'm sure there are others in the archives . Perhaps someone who is proficient at using the search function could help . There are / were a few aftermarket top manufacturers out there that you could look at to get some ideas , as well .