Hello, I was wondering if I could swap 3.0 L to a 4.0 L. New to this and I’m not really sure what I’m looking for and I can’t seem to find anything online. It’s a 2003 3.0L v6 2wd

 

Welcome to the forum

You can, but it would be the same work as swapping in a V8, which would be a better overall swap
You need the engine, transmission, computer, and its wiring harness, plus exhaust changes and radiator

There is no real matchups between Ranger engines, that ended with the 2.9l and 4.0l, which were the same block, so after 1992 different engine size Rangers were incompatible for swapping