2017 / 2018 Ford Factory 3" Receiver Hitch Extension

500# tw seems a little low for a 7500# trailer . Is it a boat trailer ?

I bought 3 feet of 3" square tubing to use as extension for about $30.
Tow 1000lb trailer for 600 miles just fine.
The only problem I had was weld inside the tubing, so I grind a grove in 2.5" adapter.
Per my calculation the 3" tubing is stronger than Torklift stinger, but did not have all the measurements for precise calculation.
500 lb on extended hitch is very serious stuff, so you be careful and do some testing before going for long trip.

With my 3 inch hitch receiver I currently use a 48 inch extension and use chain to tighten to my torklifts; but, I tow a small bass boat with not much tongue weight, about 200 lbs. I haven't had any problems towing with that extension. I also had to extend the wiring adapter.