I found an old thread between DCL70 and M21RSZ28...conclusions, as I understood it, is the Chevelle is a BB code, Camaro is EB and BE is unknown. Dave (DCL70) speculated the BE stroke may be slightly less than the EB, but otherwise looks the same.
I just bought the listed one on face book. It not original. But it does have the bracket and portioning. If you need it I will send to you. If you don't have a least replacement portioning valve and bracket and that other thing I do t know what the hell it's called