2004 DiscoII
So on both heads I have the top inner three bolts stamped with AA on top and 10.9 at the bottom. Not on the 2 top outside bolts on either side. Weird. On the bottom bolts I cant really tell since they are a little corroded.
Are these original head bolts? Does it mean anything?

 

1. No way to tell if original except by reviewing mx history.
2. Means nothing of concern unless ****.
3. If concerned consult WM or a web search for bolt markings.
......

 

The bolt that has 10.9/AA is the longer bolt that goes in the middle and the other 10.9/UNC DYTSA with a different designation is the shorter ones. Once you have the set it will come with longer and shorter ones that will match your application. You can cross reference them but Im sure it does not matter. Both 10.9 must be more specific with torque designation and the rest could just be the size.

 

Great answer. This is not my first DiscoII HG repair and so I am used to the head bolts. The weird thing on this one was that the heads looked like they may may have been changed (very very clean and new valve cover gasket/exhaust gaskets) but if so I have never seen the replacement stretch bolts with the markings on them. I was trying to conclude if the person who did the job before me just reused the factory bolts.