Transmission Kickdown

Did the Holly come with instructions? It sounds like you have the wrong port.

If you have a Turbo Hydromatic 400 there's an electric kick down switch that should be either hooked up to the throttle linkage or the accelerator pedal. Cadillac put the switch on the throttle linkage while Pontiac put the switch under the dash attached to the accelerator pedal. I'm not exactly sure where Oldsmobile put it but I'm thinking the throttle linkage since you replaced the carburetor and lost the kick down capability. Another thing to be aware of is that in 1972 GM was using an emission control device called Transmission Controlled Spark (TCS). When the engine temperature was below 100°F or above 220°F vacuum advance was supplied to the distributor. Also when the transmission shifted into 3rd vacuum advance was supplied to the distributor. At all other times no vacuum advance was supplied to the distributor. Why is this important? GM used the same style two way electrical connector for the TCS solenoid to control vacuum to the distributor as was used on the transmission kick down switch and on the air conditioner compressor on many makes and models. Over the years the TCS system got disconnected, bypassed, etc. and the plug in many cases was just left hanging. Hope that helps! Jim