Are these 340 ex-manifolds?

I have a pair of manifolds I bought years ago when I was looking for an A body to put a 360 into.
I was told they are 340 manifolds, but looking at them they don't seem much different then the stock 273 looks.
I also have a 4bbl intake manifold, early 273 (has the tilted bolt holes) unmolested. Is this worth anything?

These were going on my car until I decided to go big block!

Numbers on pass side- 3418623D
8.12.72 8ZC
driver side- 3614368-1
3.14.72 8ZC

Numbers on 4BBl intake- A1
6X24
2536563


Can anyone on here tell me what I have?

Thanks in advance, Mike