Thanks for the info ! I just about to take the VSS to the ECM. I ended up taking the passenger seat out and built a quick bench last night. Brought out a 40" screen and a desktop computer. I practiced a bunch with the emulator. Read a ton. Some of it is sinking in lol. I created around 10 bins last night using the compare tool. I did stick with $OD. Here's my concern though, and please correct me if I am off base but, I gather that all this centers down to the proper BCC for the proper ECM that is for the proper vehicle. Even filtered further primarily by engine type, trans type, gear ratio, weight, and emissions equipment. Am I doing wrong by using a bin made for a 4L60E ? The BJLF bin is 4L60E and 3.08 gears. No other bin mentions 3.08. I'm getting close to putting heads, T2, and a 750 on it :)