> Aero was the 4 valve pentroof Cleveland heads mentioned above.
  
I think you mean Arao:
 
http://www.araoengineering.com/
 
Thunder Power marketed a similar 4 valve pushrod head for the BBC:
 
http://www.bacomatic.org/~dw/chevy/bb/bb.htm
> Did I mention that those 4 valve heads didn't work? Matter of fact they 
> plain sucked.
Do you know someone who actually tried these?  Arao has been around for 
quite a while but I've never come across someone who has any experience 
with them.  What sort of problems did they have?  I saw recently that one 
of the Pantera guys bought a set of these but he hasn't run them yet.  
Dan Jones