Pic of the bracket might help.
Might be 27 body specific.
Verify, would be greatDo you need the hardware or just want to verify that you are using the correct bolts?
Mine are 1/4-20 with a free spinning washer but I can’t be sure they are original. They don’t have a tapered assembly end like the one shown in your first post - which also looks to be a little coarser thread. Mr body bracket is a little different too as it has a single captured nut mounted in the bracket. So, I’m afraid this may not help - seems Dodge did a lot of things slightly differently from Plymouth.