Credits ?

Ok I have a 2001 3.8 firebird 70mm on e85 . it is already tuned on HP but I bought my own setup to start now . my question is on credits.. Do I need to licence anything since its tuned and unlocked? Second is does the 2 credits alow me to tune back to back and make changes or do I need to do the 6 credits so I can continue tunning the car .

Yes you would need to license it.

2 credits for single vcm license that will allow you to tune that pcm an unlimited amount of times.