There are quite a few variables that determine just how "stock" were talking here...
But we'll go with a stock bore & stroke,with the pistons about .020" down in the hole (a pretty standard amount),with the usual valve reliefs (appx. -6cc's),and using a "standard" compressed thickness head gasket (.040").
I come up with a 77 cc chamber to get the 9.5:1 your looking to achieve.
Some of the later model engines used pistons with a large "bevel" in them too,so if these are being used that will affect the final numbers as well.
You can employ a slightly larger chamber if you get the pistons closer to "zero" deck height by any of the possible methods of doing so,or use the closest bore size/thin (.027") cometic head gaskets to reduce the "gasket volume" somewhat.
Here are a couple links to some good online calculators for playing around with the numbers on something like this:
http://www.rosspistons.com/calculator.php
http://kb-silvolite.com/calc.php?action=comp