I just finished listening to Adam Dunn for TH Seeds' podcast where he had Chemdog, Asshole Joe and PBud. They went over the chronology of the chem line. Sour D, OG Kush, ECSD. Basically they said that the Chem 91 cut is the ECSD cut. Also supposedly the OG line and the Chem line prolly came from the same batch, or same person at least. There is also a difference between the ECSD cut and the Sour Diesel that actually went around NY. According to Chem and Joe the Sour D was an accidental cross between a Mass Skunk and the ECSD cut. That explains why there are distinct differences in the "sour" available, there always was. I am wondering which cut made its way to the Dam to create the Dog. From the S1's that I have I would have to say it possesses a darker green color more like the ECSD and has a very "chemical/fuel funk prolly the chem 91.