What would be the best v6 to swap to I currently have a 2.5l rear wheel drive

 

There isn't one

The 302/5.0l V8 swap is what most do because its exactly the same working if you are changing engine size

Anytime you change engine size you have to change the engine, transmission, computer and wiring harness
So same work for V6 or V8

And its actually cheaper, and less work, to just buy a Factory V6 Ranger than to build one, basically from scratch

The V8 swaps were popular because you can not buy a Factory V8 Ranger