I got a set of coated Olds headers with a package purchase a few years ago. The number 58150 stamping indicates a painted Headman header in the current Summit catalog which does not make sense since they're coated. I was told by the seller they are for a small block. I've posted pictures including all the number stampings here. If anyone can tell me what they fit, I'd appreciate the help.

Thanks,
Bob D'

 

They were sent to HPC to be coated later (not by the manufacturer).

 

Thanks Copper 128. I did not understand the markings but figured there was some meaning to it. It makes sense. The part # checks out to be for big block Olds, not SBO.