Good afternoon, I worked in the tire industry for many years as an R&D Engineer. That appears to be a ply separation in the sidewall. DO NOT USE that tire. It will most likely blowout once enough stress/strain is applied.
Thanks for all the replies. I'm glad I posted this and others will benefit as well.
I will not use this tire. I'm glad I always look over my car after race day with fresh eyeballs. Hopefully Summit and MT will treat me right on this.