Am I cracked in the head?

Here is the deal. I have this convertible that just ran like crap. I checked about everything including a compression test. All the numbers were high but nothing that would lead me to believe there was an issue. I took the intake off hoping there may be a leak that I would fix and much to my surprise - I found a crack. This is a crack between the intake runners on the passenger head. I have attached a picture in hopes of someone being able to identify if this really is a crack and hopefully the problem I have been trying to fix for a year now.
http://justjeepsters.com/enginepictures.htm

 

Mark, you might get more exposure for your engine question in the "Early CJ5" forum.

hth!

 

This may not be a crack at all. I have seen lots of heads with a mark like that, the runner used in the casting is made from an upper and lower core, they sometimes leave a mark like that. If you can see light thru it, it's obviously a crack but the mark itself does not mean its cracked. My current heads have that, they were magnafluxed and said to be fine.

 

Hey you were right. I put her all back together and everything worked out great. I drove her everywhere yesterday

 

Did you figure out what the issue was then? Or did it cure itself simply during the tear down and reassembly?
Inquiring minds want to know :?