According to the Service Manual, the FC-150
vehicles received the new improved cooling tunnel beginning in the 1959
model year. The VIN number that corresponds with the new cooling
tunnel begins with #65548-19917. There are two quick checks that
you can make to see if the FC your looking at is the early or late
style. First off is the grills. When looking at the
you will notice the the fresh air intake for the heater sits vertically
behind the grill and there is no opening at the bottom to the radiator.
styles fresh air intake is kicked in at the bottom and there is an
opening directly under it to provide more air to the radiator.
Once you get inside the
cab, the differences become more apparent. On the
style there is a step down in the tunnel between the front seats to
accommodate the heater. On the
they were able to angle the heater a bit and eliminate the step
down in the tunnel for improved cooling to the radiator. One other
note, the transfer case lever was moved from the side of the cooling
tunnel to the top when the late style cab was introduced.