The F250 is still using the Visteon Sterling 10.5” axle rated at 9750 lbs. the F350 is now using Dana axles on both the SRW and DRW.
If I already owned the truck, I would not hesitate to upgrade wheels and suspension components to be able run a 9000 LB rear axle weight. On the other hand, I would not buy this truck knowing I needed upgrades immediately. If possible, change to a truck that can handle 20 percent of gross trailer weight rating plus what ever you plan to carry in the truck.
I was carrying 8000 lbs on my rear axle and weighed about 12,500 lbs GVW and 19,500 lbs GCW with my 2005 F250, so it can be done for extended miles and years safely.
