R -Vision Trail Lite Class C (B Plus) hitch upgrade question

Ok , GM chassis , good choice. Spend the money to replace any front-end parts that are near worn . If its in question, replace that part, its going to make a difference running ay max.

The OEM ‘bare chassis tow ratings’ of 9300 lbs are called baseline tow ratings.
When the coach/camper build gets added to a base chassis the weight alters the GVWR , how much weight you can haul on that chassis and the GCWR, how much weight you can tow once you determine the GVWR. Thats why it's a 3500 lb hitch.

But you can do the basic math and determine those GROSS ratings and get a general idea once you take the combo to a certified scale.
Just keep in mind, anytime you run an rv at max gross numbers you are going to compromise handling. This is not a problem when driving down a highway on a perfect weather day without deer or impaired drivers crossing your path . Emergency maneuvers while operating at full max gross is a very different ball game. Just be careful, you don’t want make ‘self weight alterations’ , it might shift all liability onto you.

We are looking at a Chevy based 2006 R-Vision Trail-Lite with a 6.0 Chevy engine on Chevy Express Van chassis. This unmodified chassis starts its tow capacity at 6500 and goes up to 9300lbs depending on the model. I understand that this is no longer the factory chassis and I understand there was a tow rating provided by the manufacturer for a reason….

While flat towing you eliminate the hitch weight portion of the equation. Thats the good part .

As said, by adding a 5000 lb rated class 3 hitch in place of the OEM 3500 lb hitch will be something to discuss with the rv manufacturer. There is good reason for them stopping at a max rating of 3500 lbs.

I don’t know what added stresses will arise on the rv frame and components but the manufacturer should be able to explain it.

Are you looking at a Sprinter or Ford Transit rv ?
It might help you to ask the guys on those specific owners forums, what they do.

In no particular order, and I haven't ever done this, but having seen other threads over the years with the same questions, you would need to verify the strength of the frame extension under the coach part of the RV as well as the entire frame and reinforce as required, upgrade springs/shocks all around, upgrade brakes all around, verify the steering system capacity, verify rim and tire weight bearing capacities, and that's the short list. Suggest you ask the Motorhome manufacturer, if they're still in business. They'll give you the rest of the list, and the caveats, as well.
It would be easier to just buy an RV that can tow your Wrangler four down without any additional modifications.

Look at the GCWR ‘gross combined weight rating’ of any rv you buy.
AFAIK, Ford and GM chassis offer more payload than the Sprinter chassis. Not that Sprinter is not capable, just know your numbers.
Get real weights of vehicles , not posted weights from brochures etc. An empty Wrangler is not the same real weight of one with its options, larger tires, racks, kayak and anything else that we all cram inside. Same goes for the rv. We all add bedding, tools, bbq’s, dishes, pots n pans and clothes.
Loading my rv and toad for a trip adds about 1000 lbs of weight.

Looking to flat tow Jeep wrangler.

What are you planning to tow ?
A car with all four wheels down or on a tow dolly has no or very little hitch weight but a trailer or boat will have hitch weight.
Make sure you scale your hitch weight if you’re towing a trailer, don’t guess at it. Don’t overload the rv rear axle rating or tire ratings. Its important if you are towing at or near the max tow rating.

AFAIK, you can't legally increase the towing capacity by just buying/adding a 5,000lb hitch to your vehicle.
If you need 5,000lb capacity, buy something that has 5,000lb rated towing capacity. The numbers aren't just based on the strength/capacity of the hitch.