I'm considering buying a late-model Ranger, preferably with 4x4. I know after 2000 most, if not all 4x4's were equipped with the 4.0 SOHC (a few 4x4 3.0's runnin' around but not many. I'm willing to buy something with up to 150,000 miles. My question is, how durable are the SOHC motors? I've...