OK, let's get this straight;
You got a pete with a sleeper you want to use as ?? A glorified bus... that's cool but...
It will have to be considered an RV and in order for that to happen, you have to have a toilet, fridge and a bed in it, more or less mounted to get it registered. Once that is done, you happen to be renovating it and took everything out but couldn't miss the races...
It is the registration thing that you have to worry about....
Oh by the way, it has nothing to do with the weight of the truck but has to do with it can haul.