Just picked up an exhaust manifold because my old one cracked. When I set it on my counter I noticed it's got numbers engraved on it. Could be normal but just curious if anyone has seen this before.

 

Better pic

 

The three I have sitting in the garage have no markings, but haven't had any work on them. Could it by chance have been ported and that would by the machinist "signature"?

 

That's what I was thinking, I'll compare it to the one i take off n see if there are any differences

 

Should be easy to tell if it's been ported by looking inside.

 

Ive taken apart numerous manifolds, and polished each one. Never have seen numbers engraved on the flange. It is definitely a machinists serial number of sorts. Or its from a major coating company and thats how they track pieces. In your case, prob doesnt mean anything.

 

That or it was tagged by a junk yard for parts inventory...

 

engraved though? That's usually paint pen...

 

Finally got around to swapping out the manifold. Same as the stock one, only difference this one is ceramic coated, no porting.