Im thinking about eventually swapping out the 3.0 V6 for a 4.0 SOHC V6. Do both engines use the same automatic tranny and how much could I get a decent engine and PCM for together in general? Also are there any DOHC heads that will fit the 4.0?

 

the 4.0 doesn't share trans with any other ranger engine. you will need trans, wiring, mounts, computer, cooling, exhaust and a bunch of other little parts and pieces.