Cast Iron Head vs Aluminum Head

[MVaughn120@aol.com]

Here's my second question of the week....going back to being a lurker  soon   
;o)
 
I'm in the process of having the engine for my 66 1600 rebuilt.   The machine 
shop called to let me know there was a crack in  the original cast iron head. 
  Last year, I picked up  another 1600 engine which has an aluminum head.  
Both are from  3-main block.    Are they compatible?  Is there any reason  not 
to switch to the aluminum head and repair the cast iron head?
 
Thanks in advance,
Shelly
Wilmington, DE
 
_http://www.311s.org/registry/1966/spl311-00058.html_ 
(http://www.311s.org/registry/1966/spl311-00058.html)