Hi, welcome Campintruck2, Sure, why not? Some teardrops have started with probably less. I assume you're taking the center or wheel channels off, make sure it is not structural to the trailer. They usually have small wheels you may need to change the axel or hubs out to get larger wheels, if you need them, depends on what the use of the trailer will be.
You could probaly fab a folding platform over the trailer from a few inches to three feet, maybe higher depending on the stability of your build and mount the box below or above, carry a tent or mount an RTT type.
There are some great trailer builds here to give you ideas, but to match some of these off road types it would depend on the frame you have to start with. There are some pretty simple rigs here as well, some off of Harbor Freight bolt together frames.
For anyone here to give you specific advice, post a pic and/or specify what the materials are in your trailer with the demensions, include the distance the hitch is from the trailer too and size of the axel and springs. Your trailer is probably built for light duty, less than a 1000 pounds like most small bike haulers but a 1000 pounds can be alot of stuff to haul, so you're good to go I'd say, just depends on what you need to carry.
Give these guys more info and you'll get some great advice....
