Help with strange substance in Lifter valley

[stumblinhorse]

I saw this when I did the new intake a while back but didn't get any pictures. Now that I have everything apart again I got a picture. The stuff is very hard and cannot be scraped. I didn't try to get crazy with it since I don't know what it is. Any help is appreciated.

 

[chryslerfat]

In the pic it looks like paint.

 

[stumblinhorse]

It is very hard. I took a screwdriver to it to see if it would scratch off and didn't leave a mark. Also it is thick. You can feel that it is a few mils thick.

 

[chryslerfat]

It almost looks like some type of assembly mark to show a procedure was completed during assembly.

 

[89.Fifth]

Yeah a heavy duty enamel will behave like that. Just a factory mark.