Usually, extenders/racks come with a weight restriction/reduction.
Are you thinking of carrying bikes ? Roof rack on the Jeep , could be an option .
The Rease Towing products web site may provide the answers your looking for. Web address in another computer that I can't access at the moment. Sorry.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.