You have a 2.3l SOHC Lima engine, also nick named "Pinto engine" since it was first used in 1974 Ford Pinto
Very reliable engine, it is 1970's design so nothing like the newer DOHC 4cyls are for power
Outside of adding a turbo what you got is what you got power wise, these were used in Fox Body Mustangs so the Mustang forums are full of ideas to add power, some are OK, others are a waste of time and money, lol, its just an older design.
They used a timing belt, which should be changed every 80k miles or so, but it is a Non-interference engine so no engine damage would occur if belt breaks.
You will have an M5OD-R1(M5R1) manual transmission, used in Rangers from 1988 to 2011(last year), very reliable, it used ATF, yes automatic transmission fluid in a manual trans, good to check level every year or so, or when changing the engine oil, running them low can cause issues, I know DUH, lol
You have a BW1354 manual transfer case, also uses ATF or there is a better Ford Transfer case fluid that's recommended, again very reliable.
Yes, your combination is rare, a custom order if its stock
Most 4cyl Rangers are 2WD because the point of using a 4cyl engine is MPG, and 4x4 weighs almost 15% more than 2WD, boxed front frame, front axle and transfer case all adds up
The manual transmission was standard with 4cyl Ranger, for the better MPG
"Shift on the fly" was the new thing with 4x4s, so electric shift transfer cases were standard, manual shift was an option