It's possible--but NOT recommended--to pull the engine, trans, and transfer case as an assembly. MUCH easier to support the trans, leave the transfer case bolted to the crossmember, and just yank the engine by itself. As said, be sure to disconnect the torque converter, and push it back from the flexplate.
On my '88, the top two bellhousing bolts are accessed from above. The bottom four are accessed from underneath, with a L-O-N-G extension and a deep 9/16 swivel socket. The bolts have threads ("studs") above the head, so that various clamps and the trans dipstick tube bracket can attach to the bellhousing fasteners. I think all six bolts had "something" fastened to the stud end that had to be removed before the bolt could come out. The nuts on those studs may be 1/2" socket size.
I used a 33" adapter--1/2" square female on one end, 3/8 square male on the other. Several companies offer them. I got mine from SK at about half the cost (or less) compared to Snap-On or Mac. What I bought seems to be discontinued. This is the newer "locking" version:
33" 1/2" Drive 1/2F-3/8M Locking Impact Adapter
sktools.com
The impact extension, and deep impact swivels are used with a 1/2" impact wrench for fast removal.