Scott , The manifolds you have pictured above may be from an early 1971 340 e-body but not an early 1970. Some early 1971 340 e-bodies have been known to have the 49-53(last 2 digits of the casting numbers) castings as the 1970 models. The 49-53 castings were the same as the 68-70 A-body 340 manifolds as most probably know.