I have a '69 CJ-5, 4 WD, factory V-6, (Buick design), with a heavy SM-420 swap, and at least another 100 pounds of "additionals". Weight is just over 2,600 pounds.
Friend of mine used to have one. It weighed at least 1000 pounds less than my old 62 FJ-40, soft or no top, 340, A833, Jeep "straight through" transfer My recollection is that the FJ-40 was over 3800 pounds by a ways
Part of the reason is that the earlier Jeeps tended to have lighter series front/ rear axles.
We got up on "Ol Baldy" around in the N end where snow didn't melt. He could "float" right over the top of the snow I'd be back there throwin' snow all over hell trying to get through it.
He sold it to some kid, who about 2 months later was "showin off" in the city beach parking lot (asphault) and flipped it right on it's side. Got his arm out and underneath, broke his arm.