Should I change heads?

[Detour]

Attachment 2384903

Originally Posted by geezer#99

What’s the casting numbers on the block and heads?
And what numbers/letters are on the pad in front of the passenger side head?
You need to confirm what you have first.

Here is a picture of the pad, I was not able to find reference to this casting when I looked last year. The numbers on the back of the block are 3858180