Ok this might sound stupid but a long time ago I took the down shift switch off of my car and I can't say I ever noticed the difference. Now all of the sudden I am thinking I may have done something stupid. Does the down shift switch that the throttle hits make a difference or is it a novelty kind of thing?

I should also admit that my trans jumps into the next gear when I get on it, before I want it to.

The kickdown switch on the accelerator pedal activates a solenoid inside the transmission. It forces kickdown, and I found it will hold a gear longer with the pedal to the metal with a properly working kickdown. The solenoid is easy to change, one wire and two bolts, easy access on the valve body. No need to do any more than pull the pan to get to it. This tranny had a bad solenoid, it clicked but wasn't working. Carquest had one, put it in, and it was fixed.