3.0l is the engines displacement, 3 liters.
There are many types of 3 liter engines, even Ford 3 liters.
Rangers only ever used the 3.0l Vulcan engine, and yes you can replace your 3.0l Vulcan engine with another 3.0l Vulcan engine.
Your manual trans Flywheel can be removed and put on the other Vulcan engine.
3.0l Vulcan engine was use in these vehicle: https://en.wikipedia.org/wiki/Ford_Vulcan_engine
BUT(big but)............Ford also used 3.0l Duratec engines in some of these vehicles as well.
Look here: https://en.wikipedia.org/wiki/Ford_D...6_engine#3.0_L
The 3.0l Vulcan and 3.0l Duratec engines are not related in any way so not a plug and play swap.
If neighbor has a 3.0l Vulcan then you will only use the Block and Heads.
You will use your current upper and lower intakes and exhaust manifolds.
Also current oil pan and oil pump pickup