[QUOTE=jjtrujillo90609;368202]I have a 1967,F250 with a 390FE and a NP 437. It really works great and I have 3.50 gears . I turn approx 2600rpm @ 80mph. It all seems to work really well for a combination work truck and towing rig. I generally use it for highway and long distance towing when I transport my horses. I have used this combination for approx. 6 years without a hitch.