You can try towing without them, see what happens. But if you experience unwanted behavior, be prepared to install both. I'd surely try it first without. I loaded my flat utility trailer with more than 3369 pounds and towed it with a Chevy S-10 many, many years ago. Never had a problem. Try it, see what happens. Chances are, you'll be OK.
You will need brakes on the trailer and a brake controller in the truck though. No getting around that. (Indiana requires brakes on any trailer with a combined weight of trailer and cargo over 3000 pounds).