Since this has been a very lengthy post, some details get lost. At minimum you need a new #6 piston and ring set. We never seemed to figure out your bearing issues. Have you plastigauged to see the condition...meaning gap/ clearance. Are you replacing any? Mains or rods? Can you just buy a ring set for 1 piston? I would guess its probably ok to reuse your headbolts but you need a new head gasket and oil pan gasket. You started off with a suspect harmonic balancer if I remember...what was the outcome of that? Bottom line...put together as is and you get several thousand to 150 k on it...semi rebuild and same result...total rebuild and your tranny eats itself in 6 months.Its poker with 35 year old cards. If we could see the future...you would have a garage full of lionel trains that your parents didn't throw out..lol

 

haha yes that is so true. No real point in going crazy polishing on one part of the jeep when the floor is rotting out in the back. But it’s easy to go deep into the hole and lose the big picture. Thanks for your reflections!

this has been a lengthy post for sure… I was hesitant to take the engine apart and desperately wanted the knock to come from something else. Thus the new HB (installed, all good) and a spare flexplate sitting in my garage.

got a new/old piston for #6 that looks in good shape, rings too. My plan is to just drop the pistons in with the old rings. Got new head gasket, oil pan gasket etc waiting to go in too.

now: cleaning and inspecting
next: put pistons in and plastigauge for bearings next next: total assembly

 

From your last few pictures, it shows that you have been way more than minimally thorough . For a tiny bit more in expenditure you could save yourself days of lying on the floor. 2 motor mount bolts and 4 tranny bolts and that block is out. A hoist and engine stand is pretty cheap from harbor freight or similar and you could put it all back together standing up with no super awkward leaning over fenders and such. My one note of caution...that engine bay is an unworkable mess as is. It needs to be emptied and cleaned if you want to reassemble in there but so far so good best of luck with it

 

You forgot to mention the absolute PITA that the top bellhousing bolts are and the fact that they require a t12 socket which most people dont have laying around. Obviously hes been doing fine the way things are. This isnt the worlds first in frame garage rebuild of a 4.0.
Yes it would be more convenient, easier to work, etc to have the engine on a stand, but its not a necessity.
I would definitely have had the header panel off already though. Thats the first thing I do for any major work.

 

I get both your points here. Just getting the head off was a big step for me. Getting a hoist and a stand is just too much next level although I get it could potentially save me a chiropractor bill later.

getting the header panel off is a good call, thanks!

my biggest concern now is that my garage is around 23 degrees (with a heater full blast), any soapy water turns to ice and I will most likely break any bolts I try to torque to 110…