Cylinder Head Thickness and Comp. Ratio

[Gameparker@cs.com]

Dear List,
my second head is in the shop awaiting my instruction as to what thickness it 
is to be
 milled to, in order to attain a compression ration of about 9.5:1  They seem 
unwilling to
 take off more than 30 thou, suggesting more a 20 thou skim.  I just need 
someone with
 a competition manual to look up what the final head thickness should be.

Thanks and Regards
Geoff Parker
74 TR6
CF17470 U O