It's not a 71 lid. The Road Runner and GTX both had the round lid with the 383 or 440-4barrel, owned many 71 airgrabber cars, all round lids except the hemi and 6. And I believe most the 70's also received the round lid with 4 barrel. The lid you have is definitely a 4 barrel lid, the 6 barrel had the rear hole farther back. Looks like a 69 or possibly an early 70.