You're talking about the cracks between the two valves ?
Totally normal.
You 'could' get them pressure tested if you're worried,
You can also peen the cracks shut with a hammer and punch.

Fwiw - ..judging by the corrosion where the water gasket touches this head -
perhaps you might get away with head gaskets only.

I would also test for valve sealing by filling the ports with gasoline or
kerosene, and see if they leak. I usually find at least one exhaust valve
leaking.
Then I have a machine shop do a valve job.

And what I wanted to say about AMC heads - fwiw,  I have one.....that I
installed new, and it didn't last, for head gasket sealing .....that
particular head is so far out of 'dimension' it's sick.     Pure junk.  And
it was factory new.  So I'd be careful about AMC heads, if nothing else.  

I'm finding it necessary to check how much the water gasket gets compressed.
By my measurements the water gasket is 3.7 mm thick.
Put the head on temporarily ( with metal sealing rings at the top of the
barrels ) and measure the water gasket  gap.
Iv'e seen  it be 3.7 mm - thus no compression on the water gasket - and it
leaked after a thousand miles. 
Iv'e seen it vary , like 4 mm on one end, 7 mm on the other, and so forth.  
And I'd be real careful with AMC heads.
I'd rather have a good set of used non-amc heads and rebuild them, then
install them, than use AMC heads, unless the measure out nicely.
Scott
www.turbovans.com 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Chris Lisica
Sent: Sunday, September 09, 2007 7:35 PM
To: vanagon@GERRY.VANAGON.COM
Subject: cracked AMC heads question

Volks,

After purchasing my wife's 87 Westy project, I'm finally getting started. I
knew the heads were messed up, but I was hoping for a simple head gasket
job. Upon closer inspection, and a few pictures in macro focus mode, there
appears to be a big crack on the one side. Any opinions? Is this head
reusable? What could cause such a large crack? The pics:

http://wavanagon.googlepages.com/amcheads

Please help enlighten an aspiring Vanagon mechanic. Thanks for any
advice/input/feedback/links/etc.....

--
Chris
88 Vanagon GL (daily driver)
87 Westfalia (in progress)