I have questions about trailering. I have a 2007 Silverado Work Truck long bed 2WD with the 4.8L V8 and Auto Transmission and 3.23 rear differential.. I added the receiver trailer hitch / 7 pin trailer plug and am adding on a transmission cooler and brake controller . The owners manual says the MAX trailering weight of this truck is 5000 lbs with a conventional trailer / RV. I have found a couple of light weight 5th wheels in the 3500 lb range which should keep me slightly under the gross. Owners manual also says that 5th wheel gross trailer weight is 5000 lbs but lists it as a 3.73 rear differential needed.
Why would this be? 5000lbs I would think would be the same towing either way.
Finally, If I stay within the gross weight limits, Will I have problems towing with this truck?

Thanks
Jim
Kingston, TN.