Timing question

First of all the car runs great no issues at all. I am looking into nitrous and wanted to check what my timing is currently set to instead of assuming it is set to 6* BTDC. I warmed up the car then shut it off disconnected the EST restarted and timing appears to be at 2* BTDC. My timing tab has the following info stated on it. Not sure if it is stock or not

Before After
Top of tab states 12 | 8 | 4 | 0 | 4 | 8

My Damper line matches up to the line between 4 & 0 on the Before side of timing tab @ IDEL

The kit I am most likely going to get is the Harris SpeedWorks Sunden impact. Their Tech states no retard of timing for up to 150hp. I know some say do and some say don't. Well that leads me to my question should I just leave my timing as is @ 2* BTDC considing I will be using NOS or reset it to 6* BTDC? ? Thanks for your time!