1990-2000 Rangers used the 4.0l OHV engines
2001 and up Rangers used the 4.0l SOHC engines, completely different engines
4.0l SOHC had a balancer shaft added inside the engine on 4x4 model Rangers and Explorers.
This was added because Explorers were AWD, and in 2001 Rangers got "Live Axles", the front wheels were always locked so front driveshaft would always spin when vehicle was in motion.
It was done to counter act front driveshaft vibration
Engineering wise and on paper it makes sense.
But people have been running Rangers with front wheels locked since there first were 4x4 Rangers and manual hubs.
No one ever complained about a vibration......unless there was something else wrong, lol.
And many have swapped in a 4.0l SOHC with balancer into 2WD cars/trucks,
and a 4.0l SOHC without balancer into 4WD trucks without any notice of vibration.
Mustang 4.0l SOHC can also be used, less torque but higher horsepower cams
So yes it will work fine.
You may need to swap upper intakes, that's a model or year issue, they moved sensors around so you need to swap it to match your 2001 wiring.
And always replace rear main seal.
1997 to 2004 4.0l SOHC engines had poorly designed timing chain cassettes, so they should be changed to the newer design.
Last edited by RonD; 06-14-2016 at 09:11 AM.