Last month, I bought an 86 Ranger Diesel and have been trying to find all the info about this motor as I could. That's what led me to join this site...I didn't know the D50 came with the same motors as an option. I'm in the middle of replacing both timing belts are a precaution...as well as other little things that I've found. One of which is the coolant temp sensor for the dash gauge. The old one resembles a Ford knock sensor and I don't see the portion that sticks out into the coolant stream. Can I replace this with a more modern sensor? I've grounded the plug that goes to the sensor and the dash gauge slowly swings to full hot and a buzzer starts sounding about half way, so all that is working properly. Also, why does the sensor appear to have 2 prongs, yet there is only one wire going to it from the wiring harness?

Next is the air filter. It still has the stock air box on it, and the only number I can see on the old filter is 546131. It has an orange outer foam material, so I was thinking it might be WIX or Fram or Purolator...yet I can't come up with anything using the 546131 part number. Any ideas?