Iron "log" exhaust manifold numbers?

[Andrew]

I’ve got a set of em I'm planning on putting on ebay (or make me an offer) there 383 I think they came off of a 70 imperial (the engine that was in my truck) but I need to make sure. is there anyway I can check the numbers? I look for the noticeable, aka if it had a "70" in the numbers at all I didn’t see one. thanks!