It's not worth the trouble. You'd find power going from a sohc to a dohc motor but its probably going to involve a lot of searching for parts and probably having some custom parts built. It should also be noted that being that Ford never made a dohc 4.0 its pretty unlikely that your friend has one, although its not impossible. From what I understand the Ranger and Explorer 4.0's are the same as the 2005+ Mustang after 2001, but they're ohv instead of sohc before 2001. An ohv swap would probably be easier, but would require that you get an ohv 4.0 and convert it to dohc and then swap it with your current sohc 4.0. As I said before, not worth the trouble.Is it worth the trouble/possible to change an 08 v6 4.0 sohc engine into a dohc engine. My buddy at least says he has a 4.0 explorer with a dohc engine. is it possible to swap the two, to make the v6 better? and if so how much trouble would it be?