Yesterday we pulled an 88 5.0 HO out and I took a good look at the block.
On the passenger side rear, inboard of the upper most bellhousing bolt and inboard of the bellhousing ring is a large rounded cast in boss about the size of a small chicken egg. This is directly below the flat machined surface.
It appears this cast in boss is there doing nothing,
so maybe there is some instance that they might tap a hole into it for hoisting as suggested in a previous post.
Never really noticed the boss before, and never have seen any with a hole.
I personally have a 90 HO fuelie and a 90 TownCar and neither have a hole.
I might suggest that it is a place for a knock sensor since the 351W engine used in my 95 EddieBauer Bronco had a knock sensor in this same location which I had to replace.