[ERA Chas]

Yes, my heads are Shelby Stage II but that means different things to different heads. Stage II generally means CNC ports, runners and bowl blending. (As well as CNC chambers) But BT, Brodix and Ede can mean different port sizes. They should all be right near 'medium riser' configuration and size. My ports are 2.080 x 1.38. The 1247 S3's are 2.10 x 1.40. They fit the ports perfectly and the bolt holes and water ports are perfect too.