1969 small block smog tube questions

[dvss1]

Picked up these manifolds 826 and 527. My question on the 826 manifold it has a different shape smog tube I have never seen. Both manifds are dated I 1 8 and I 17 8. We're there differences in the early to late smog tubes or cars that got air conditioning?

Thanks SYC

[rszmjt]

Does the drivers side tube have a flattened area above #1 cylinder area? Its hard to tell from the photo. If it does it is 1972 up. I have seen that rh tube with the raised area before on vacumn pot controlled heat riser applications such as 73/74 Nova etc. with AC