Throttle cable and kickdown cable pulling hard

I have the lokar setup on my 273/904 combo. The action is slightly stiffer than factory was but not enough to fret about. I adjusted the kickdown to fully engaged at WOT and have about 3K on the car since completion with a 700 mile road trip and no issues whatsoever. Good equipment imho.

Are you running a return spring on the kick down lever at the transmission?

I'm also wondering if some fluid and running the engine won't make a difference in the kickdown lever/ internal piston stiffness.