69 BB radiator shroud

[camaro cat]

I asked this question in the parts and memorabilia for sale section as there are currently both assembly line and over the counter versions for sale. I'm not sure if I see all the differences between the two so I'm asking for help to know the differences. I decided my question didn't make much sense there so I'll move it here. This is what I posted: Question. Is the difference between the assembly line version & OTC version, those 3 ridges I see on the over the top rise on the top front of the one on the left? They have the same pn#, & date clock with a 68 in it. Am I missing something else? Mine is like the one on the right without the ridges and said to be an assembly line piece. But I did buy mine from my local Chevy dealer parts counter, although a loooong time ago.

Thank you

Loren