Engine Inspection Marks

[Rooster]

Has anyone else found these markings on the side of an engine?
Does anyone know what they mean or where to find out?
From a 69 440HP2
Markings on driver side look like a G or 6? BB L

Passenger side a D, then hard to tell through picture but close inspection looks like a 6

 

[moparnation74]

They equate to the actual bore size of each cylinder....it is for proper assembly purposes at the factory....

https://www.forbbodiesonly.com/mopa...gtx-restoration.127388/page-26#post-910700455

 

[Rooster]

Appreciate it.
Did every single engine have this?

 

[moparnation74]

Appreciate it.
Did every single engine have this?

Yes....