Throttle/Kick Down Linkage

SLC, yours is like that because the intake manifold is taller than the stock one. Someone ran out of adjustment. As others stated there are solutions for the issue.
This, exactly. The problem with eliminating the slot......and the reason that Chrysler engineered it with a slot is so that, in the event that the transmission linkage binds or locks up the throttle can still close. Another reason to go cable. I am currently modifying a cable set up from a newer b van to work on my 55.