Howdy. I've got a 1997 Mistubishi Montero that needs an engine. It's a 3.5 SOHC. I purchased an engine that was advertised as a 1997-2002 3.5l V6 SOHC Montero engine. However, the engine I received is a DOHC model. Got it shipped and my mechanic noticed they were very different when he got the old one out of my car and was ready to put the new one in. Now, this has turned into a huge hassle. What is the feasibility of swapping 3.5 SOHC to a 3.5 DOHC? It seems very very impractical to me and my limited knowledge, but I decided to ask, just in case.