Need a full replacement. It's a 2005 ranger stx 4.0 sohc 5 speed manual. What year range would be a straight swap. In regards to wiring harness etc. Thanks

 

2005 Ranger 2wd 4.0l SOHC would be only direct swap

1997 Explorer 4.0l SOHC and up if you use your current upper and lower intake and accessories
2001 Ranger/Mazda 4.0l SOHC and up if you use your current upper and lower intake and accessories.

The 4.0l SOHC Blocks and heads(long block) do have differences from 1997 to 2012, so you need to know the engines year when buying engine specific parts in the future but overall there were not that many changes.
i.e. your exhaust manifolds and intake will bolt to 1997-2012 4.0l SOHC
intake has all the wiring connections which is why you want to keep that with the truck

If you have an automatic and engine you get was from a manual you will need to remove it's flywheel and replace it with your flexplate, or visa versa

 

Thanks a lot man

 

Only downfall I reckon... The only good, running, affordable one I've came across..that I can see and hear run before purchase..is out of a 96

 

That would be a 4.0l OHV, so not the same engine, Ford used 4.0l OHV from 1990-2000.
1997 was first year Ford installed/used the 4.0l SOHC engine, Explorers/Mountaineers were the first to get them as an optional engine, they still used 4.0l OHV as base model engine until 2001, then Rangers and Explorers/Mountaineers both had 4.0l SOHC models, 4.0l OHV was discontinued in 2000.
Mustangs used the 4.0l SOHC from 2005 to 2010, think it had different cam than truck model, so less torque but more HP.

The early models, 1997 to 2004 had a fault in timing chain, cassettes, and tensioners, these need to be upgrade to the newer design, after that they were fine, so just a heads up if you get an older model.

EDIT: I also remember reading that in some areas where there are emissions testing you can't swap in an older engine, if you are doing all the work yourself and since it is the same type of engine that shouldn't be an issue, they don't check engine numbers, just VIN, and your VIN will just have "E" as engine type, 4.0l SOHC engine.
8th digit in VIN is engine type, 4.0l OHV was "X"