There is so much aftermarket stuff on that, its hard to tell what year or model it actual was.
If you are serious about the running gear you are talking about, do yourself a favor and buy it, take the body off and put it on a K5 chassis and call it a Jeep.
I drove one of those for 10 years as my DD. Also my hunting vehicle, dating vehicle, whatever.
There is nothing I do not know about fixing one of those.
Trust me when I say I can do a complete front wheel bearing change blindfolded.
In mud.
I know, because I did one one night with no flashlight, matches, or moonlight and in the rain . Completely by feel.
Over the years, I completly rewired it, replaced every part of the brake system, pulled the motor and put it back in after a rebuild. Rebuilt the front and rear ends. I had someone else do the transmission, but I changed the needle bearings in the transfer case whenever they got too loud.
Until the wonderful day I found the tapered roller bearing aftermarket kit.
Those little things have a reputation for toughness.
And its earned.
My old Jeep would drive over or through what they are calling Jeeps these days.
But, the main reason they got that rep, was because they were so well balanced. The 134CI Hurricane motor would crank out 90Hp on a good day.
The clutch, transmission and transfer case could take everything it could put out.
And the front and rear ends could handle the torque.
I have often swore that the suspension was designed to break the driver before it broke.
If you started trying to jump ditches or things that might damage the suspension, you got lots of....lets call it feedback, telling you that you were reaching the limits.
You could drop a Buick V6 in it, almost a direct swap. It made a huge difference in the vehicle.
And things did not get too fragile. If you were not too crazy, everything would stand up.
Anything above that, and you were asking for trouble. You would break the transmission, drive shafts, axles, something was going to give. And after you fixed that, something else would give.
I know people do the kind of things you are talking about, but if they keep much of anything original other than the body and maybe the frame, I would be surprised.