There are early and late servo's on that control the bands but the PT kickdown unit is not actually a servo, it's a valve assy. The only time I tried it to install a PT kickdown unit I had the PT kickdown from a 76 VB and tried it on a 73 VB and it it wouldn't work due to missing and mis-aligned passages. I think I remember Mopar offering a PT kickdown unit for the old valve bodies a long time ago so maybe they were what you used??
