I did this upgrade myself. I have an 87 BII (2.9, M5OD) that was originally automatic, and used a new radiator for a 94 Exlporer. It was an easy swap. Under normal driving conditions, it cools too much. I have to block off over half of it.
Even with 100+ degree weather for over 50 days, the only time my engine got up to normal temp. was when I took a 3.5 hour road trip at 65 miles an hour, in 105 deg. weather. Now that the temp outside is between 35 deg, to 70 deg., it never gets above 180 degrees, verified with a thermometer.
I noticed my mileage went down, I believe because the engine is running cooler and the computer is running the fuel richer. I read theories that this would produce more power, but I didn't notice any real difference.