TH 400 kick down switch

[POWERMAD]

I just installed a new carb and dropped an HEI in my buddies 70 GMC with a 402 BBC/TH400
I noticed that it won't kick down. There is no switch that I can see by the pedal or the carb. It has the rod type throttle linkage.
Anyone know where it is supposed to be ?
Thanx
Ron