what are these numbers?

[Ole Buck]

located on the inside of my 5.3 head. The laser etched numbers and letter.

You must be registered for see images attach

 

[bucket]

Does the other head have a number etched into it?

 

[Radiohead]

A serial number?

 

[wuznme]

Production run numbers, so they can keep track for recalls etc...

The only number that matters is the 3-digits above, those are the model specific heads; those are 862's

 

[Ole Buck]

Does the other head have a number etched into it?

Yes sir.

You must be registered for see images attach