1955 2nd series to 1959 Task Force 4x4's.
More than likely, they will be the NAPCO system. However the '55 2nd series, if original, will have the Rockwell transfer case. '56-'59 will be the Spicer transfer case.
The '55 with the Rockwell will also be a twin stick (One stick engages the 4x4 and the other stick is a gear reducer for a HIGH and LOW side, and will have a drivers side pumpkin front differential. '56-'59 Spicer units will be single stick (2WD, 4 HIGH, NEUTRAL, 4 LOW) and have a passenger side pumpkin front differential.
(HOWEVER.....There are, a very few, '56 with a Rockwell, twin stick, AND passenger side pumpkin front differential. These are extremely RARE !!! (The '55 and '56 Rockwell cases look identical but are mirror images of each other!) Possibly a transition case before the Spicer was decided on.)
The '55 used a 3/4 front axle housing with a 1/2 (3.90) running gear and front brake system was '55 3/4 ton single push wheel cylinder set up. '56-'59 was a new set up for the passeger front differential and used the duel push, step up, (one side of the bore larger than the other side of the bore) wheel cylinder.
As far as the Task Force trucks, how's that, for throwing a wrench at your WOOKIE !?!
