how low can i safely lower shift firmness in 4R70W with SCT?

[04ctd]

had my tranny rebuilt in the 99,

and put a mild shift kit in it.

due the number of variables in a 135k mile tranny that has been rebuilt once at least,

it came out a LOT firmer than we thought.
not too firm for one of us,

but too firm for my Dad.

i have them down 10%, it goes in five % steps down to 25.


it also allows you to change the MPH, but i have not monkeyed with that.

??