1968 Z/28, SS350 Valve Covers
 

Hi folks,

Trying to figure out if these are GM or reproduction. I have had them for years - they came with other '68 302 parts so I assumed they were originals, but they don't have the 'O' stamped into the flanges. Thoughts?

https://photos.smugmug.com/SYc-Site/...95A30A9-X2.jpg

https://photos.smugmug.com/SYc-Site/...B582314-X2.jpg

https://photos.smugmug.com/SYc-Site/...50FA4F3-X2.jpg

https://photos.smugmug.com/SYc-Site/...F17CFCF-X2.jpg

Wasn’t the “o” only an assembly line inspection marking?and I think service replacement parts don’t have it.

Ah, that would make sense! Appreciate the guidance.

Motorhead 848 is correct. I had an NOS set, no stamp.

Thanks!

these were also used on the '68 L79s

I have a used set that I could take pics of to show for comparison.

Thanks guys, I have another set that came with my '68 Z28 which have the 'O' stamped on the flange. I was confused as to why these didn't....

Appreciate the help.

I have heard that the "O" was a locating mark for the assemblers - that those marks are supposed be on the intake side when installed; if you look closely the covers are longer / taller on one side for rocker arm clearance and we've all seen the marks made on the inside when they're installed backwards, and likely heard the difference too. Cheers.