Hitch receiver for a spare tire?

I don't believe the concept of that leverage on the TJ Unlimited is fully realized by most. The last one we set up coil overs on was dialed in to get the ride height exactly where we wanted it. The owner brought the spare over and we hung it on the swing out. The back went down about 3/8"ish, the front went up over an inch.

Sounds familiar. On my short TJ with it's heavy carrier, I consistently needed LJ rear coils to get the rear ride heights I was after. And the front would have a lighter coil than what others would typically use. I'm not familiar with the weight distribution on an LJ, but I can imagine that the teeter totter effect could be greater with the larger overhang.
 
So the con is that it’s dangerous to put that much weight outside of your wheelbase because you get a bounce and your coils are flexed unevenly? Is it dangerous on roads?
I will use my rear hitch cargo rack to transport firewood. When it’s loaded up, it definitely turns my driver’s seat into a lazy boy recliner. I can feel how far back the Jeep is flexing. Is that dangerous?

Plenty of people do what you are suggesting without dying or inconveniencing others. My experiences come from time and miles and a desire to observe and refine while wanting a Jeep that can do many things while behaving well on the highway.
 
So the con is that it’s dangerous to put that much weight outside of your wheelbase because you get a bounce and your coils are flexed unevenly? Is it dangerous on roads?
I will use my rear hitch cargo rack to transport firewood. When it’s loaded up, it definitely turns my driver’s seat into a lazy boy recliner. I can feel how far back the Jeep is flexing. Is that dangerous?

Load it up and try braking hard as if someone drove out in front of you. Does your stopping distance change?

Try going over some potholes and swerving. Does the Jeep feel any more uncontrolled than it did before?
 
I’ve actually done some mid range off-roading with about 100lb on a hitch rack. It’s not bad off-road so long as it never touches the ground or boulders.
On the freeway, I feel more prone to death wobble and slow it down a tad. That said, I’ve hit 85 with the setup and it was fine. Just a little sketchier than normal.
 
Here’s an idea of what I’ve been riding around with. Most recently I had significantly more wood back there but didn’t take a pic

B9454178-0C30-4A90-8463-F88A255A4475.jpeg
 
You might also consider one of the over-the-tire racks.
Here's an example (tank mounts are separate):
RH-2004-3T.jpg

I like the one in this photo because it's decently sturdy and adjustable height
(Rock Hard 4x4 "Rock Rack").

There are some other good ones out there too.
 
You might also consider one of the over-the-tire racks.
Here's an example (tank mounts are separate):
View attachment 94939
I like the one in this photo because it's decently sturdy and adjustable height
(Rock Hard 4x4 "Rock Rack").

There are some other good ones out there too.

For firewood? All the way up there?
 
Of course it is. If you can feel the front end floating that means the steering and brakes are floating too. That is why you see most tractors with a ton of weights hanging on the front. And those are machines made to have heavy stuff hang off the back. Pack less or get a roof rack. But that will open up another can of worms.