Well, by just turning up the high idle screw, you are putting a higher preload on the gov spring when the throttle shaft rotates further than stock. Ok, now you will need to grind a relief in the bellcrank support so the throttle can move far enough to use the extra throttle lever travel. Now you get to deal with KD adjustments. Remember, there is only so much travel in the KD cable, so, you may have to deal with improper KD adjustment. What I mean is, in order to get full travel at wide open, you may not be able to get the proper closed throttle adjustment. And with a Torqueflite trans, you will kill the trans in very short order if you run it with the KD cable out of adjustment.
If you run the 3200 gov spring, you won't have to deal with any of this.
I just installed a spring in my sons truck and it took 40 minutes. It's not that big of a deal. And you can remove the top without removing the throttle shaft. Just use a 5mm ball end allen wrench. And back the power screw ALL the way out. Look at it and you will see how it is done. And you can always go to a pump shop and look at a pump.
Dave