On the 4.0 there re core plugs in the ends of the cylinder heads as well as in the back of the block (under the flywheel all are an absolute BASTARD to access with the engine or trans in the chassis...
Good luck.
My "Boggle" at the moment is discovering my passenger side motor mount is "Fooked"
which allows my 4.0 to sit low on that side resulting in the cat flange of the Y-pipe to hit the lower flange of the frame before I can get the trans tailshaft to move enough to the passenger side to allow me to get the tranny mount studs to drop into the holes in the cross-member.
I hope your problem isn't an engine fatality, I keep TWO spare 4.0's on hand to deal with that possibility.
I've never had a lot of money, so I need to be ruthlessly methodical to plan for "Mechanical Disasters" that inevitably occour...
MY having parts on hand has saved the bacon of an awful lot of people who don't have the storage space to keep spares...
I can't even recall the guys who were 4wheeling across the country for an article for some 4x4 magazine and U-boated their 4.0 Bronco2 and needed an engine (Can't fix bent rods)
when Jim called me and asked if I had an engine for them... Yep I did On 2hours notice I had it out where they could get it they showed up and away they went..
The funny part Is I had another engine from the junkyard (that I saw running before they pulled it for me) hours before they had the engine they got from me into their B2
I have one regret... they were putting it in a B2 with an Auto Trans, and I forgot to pull the clutch and flywheel off of it before the engine left, which caused me trouble later...