From OP's profile: forest river microlite 25ds w toyo tundra extended cab
So the question is what does he have that weighs 300 pounds that he can move to the rear of the trailer????
http://www.barrettrv.com/New-Inventory-2015-Forest-River-Micro-Lite-25DS-Queensbury-New-York-754375Being a bumper pull moving weight to the rear of the trailer is not a good idea!
On edit: I appears that the OP has a new truck and 5th wheel. He was trying to purchase a 3500 GMC, but may have ended up with a 2500 because of availability!! So we need more info!!!!
Chris