1964 C30 Towing Capacity

I have a 1964 C30 Dually completing a full restoration, replacing the 230 - I6 and 7200 lb rear H072 axle 5.14 gears, with a remanufactured 350 cid with Max Flow EFI-500 fuel injection, remanufactured 1980 14 bolt 8000lb rear dually axle with 3.73 gears, added double reservoir power brakes. All drum brake hardware rebuilt or replaced with new. New remanufactured SM420 with Novak front seal upgrade and added synchronizer between 1st and 2nd gear, final gear ratio 1.0. I am looking to tow a 5th wheel in the 5000-8000 max range. I won't be towing often, a couple of times a year between Virginia to Tennessee. GVWR on the truck plate is 10k. The trailer will have brakes. I won't be adding disc brakes, and surely looking way ahead with the setup while towing.

Let me know your thoughts on if this is doable with enough margin for a 5000-8000 fifth wheel RV.
Thanks