Throttle cable / gas pedal "stiffness"

[beermunk]

I was wondering if this is just my ignorance of having an old vehicle or if there is something I can fix here.

The issue is that the gas pedal seems stiff when initially pressing it. After it's down for a little bit it has the same resistance as I am used to in driving a new vehicle. It's really noticeable when I'm in 2nd gear and initially hit the gas. I get a jerk in the throttle.

The only way to remedy not jerking the tranny like this is ride the clutch a little bit but I don't want to continue to do this. I've already given the throttle spring some wd-40 and sprayed some on the accelerator pedal.

Any thoughts or is this just the way these old trucks run?