It's called the clutch underpan. The shop manual says you can remove it to access the clutch retracting springs so I believe it should come off okay.
The flywheel is close to the block so you may not be able to see much.
The rear main seal is a common source for oil leaks at the rear of the engine.
There are metal plugs at the rear of the block that rarely leak oil.
There is also one large metal plug that rarely leaks and if it does, will be coolant.
Oil can also leak from the rear of the valve cover and sneak it's way between the clutch housing (bell housing) and the block.

The rear main rope seal needs to leak a little oil (weep) in order to form a seal.
Same as old tractors and boat propeller shafts.
Attachments
Rear Block Leak.jpg (59.27 KB, 99 downloads)

Last edited by buoymaker; 06/07/2022 4:16 AM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."