Can a shift kit go into the 4160E Transmission without any custom tuning? Will it harm it if it is not? I had ion custom tune a computer for me on my car in the past. I did not send the computer back when I got the shift kit put in. Will this hurt or hinder me car. Any thoughts?

 

I do not reccomend tuning the computer for firmer shifts if a mechanical method is used aswel.