I don't believe you would want to do that.
I was the head engineer at an aluminum extrusion plant in the U.S.
Consider this - Anodizing is a process where your material is etched in order to accept the anodic coating.
By etching your block, you are affectively removing material from every surface. This would effect the tolerance built in to every part of your block that would then require re-tooling, re-boring, etc.
You may want to consider stripping your block and contact PPG about any anodic application they may have.
What about powder coating? You can get reflective colors that mimic anodizing from your powder coater.
