I have a 351W/C4 combo in my 1950 F-1 with an Genie floorshift and Lokar AT Kickdown cable installed. Prior to installing the kickdown I test drove the truck and the transmission shifted pretty smooth from 1st to 2nd but struggled getting out of 2nd to 3rd unless the revs were high. Is this a result of the lack of the kickdown at the time or something like the modulator? All help appreciated.

 

Nope, the kickdown is exactly that, a down shift into a lower gear, sometimes called “passing gear”.

Yep, sounds good to me.

 

Shifting speeds are controlled by the vacuum modulator. The modulator has to receive vacuum from the intake manifold. At the modulator, you pull off the vacuum hose, and using a small screwdriver you turn the screw out (ccw) to lower the shift points. The kickdown linkage is adjusted to just kickdown at full throttle. This is easy to set because you can feel the spring tension on the kickdown rod when you move it all the way forward.

A Note: Since there is more vacuum at sea level, the shift points will be lower than one which was set at 4000 feet. So when it is set to shift properly at sea level, it will shift at higher speeds when you go to higher elevations....

Regards,

Alan