This link shows Appliance headers for Chevelle plus where the p/n is stamped. Yours are close but not exactly the same.
https://www.yenko.net/forum/showthrea...58#post1293358
I don't think they will work on a '67-'69 Camaro because of the #7 tube. It looks like it would interfere with a Camaro steeering box/pitman arm.