Originally Posted by
ford390gashog
That engine made 95hp in its day so getting to 55mph will be test on its own don't plan on going any faster than that.
The diffs if it was a marmon conversion should be 6.48:1
1971 was the first year Ford offered factory installed 4WD in F600's.
The way to determine if it's factory installed 4WD is by the AXLE code found on the Warranty Plate, and/or by the first 3 digits of the VIN.