someone says wrote:
4000lbs is the "advertising" payload number for a barebones truck with no options.
Actually Dodges payload numbers are for that particular packaged truck.
Looking at Dodge Body Builder guide has payloads for a .....
ST tradesman...
SLT...
Bighorn/lonestar SLT...
Laramie...
Longhorn...
They all show a different payload numbers per their package. Granted other options may be added and may change the payload rating by a 100-200 lbs or less.
A DRW has a lower towing capacity but a higher payload capacity than a SRW truck and the higher payload is the deciding factor
Again when we actually look at the numbers the Mega Cab DRW has up to 29000 lbs tow rating with the Aisin and 21000 lbs with the 68RFE vs 17xxx lbs for the SRW with the 68RFE.
IMO the SRW Mega will handle the size 5er the OP is looking at just fine. I also wouldn't go strictly by a payload number but would recommend weighing the trucks axles separately. That will tell the owner how much weight is left for a payload.