Hmmm, looking at your sig, you YJ is lifted quite a bit and has 35's on it. I would not flat tow it with your KJ because the heght of the centerline of the tow bar will be much higher than your hitch and the tow bar would not like it.
I have experience with this and my FJ40 with 6" of lift and 35's. Your YJ is probalby leaf springs so you have to make sure you get your alignment to factory specs including castor and camber or it will not flat tow at all...been there.
I found it impossible to flat tow my FJ40 because of those reasons. I had to once, I rode in the 40, and my wife towed it with a tow bar in the KJ for about 5 miles. At one point, the 40 decided to lift the KJ's rear wheels off the ground on a slow, banked corner.
