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Has anyone cc'd various I-5 cylinder heads?

One of the great imponderables about building a hi-po turbo engine (at least
for me!) is what compression ratio to run.  If you keep it low to allow for
high-boost, you typically end up with poor off-boost driveability; if you keep
it high to improve off-boost driveability, you tend to limit your ultimate
power capability.  Of course, it's not quite *this* simple -- there is an
exception to almost every rule, it seems -- and ultimately there is no
alternative but to actually build the engine then test it to see how well it

However, because I'm on a limited budget (and it seems to be getting more
limited every day!), I'd like to leave myself as much of a margin for error as
possible.  I've already found a source for custom head gaskets of varying
thickness, which will allow me to experiment a little bit with different CRs
(say, +/- 1 point) after the engine's been built, but I'd also like to know
what's available in terms of combustion chamber size for the various I-5 heads
Audi used before I order the custom pistons for my 2.5L project.  Since
swapping heads is easier and potentially cheaper than building another bottom
end, I would like to give myself a second chance at correcting things in case
I get it wrong the first time around...

Has anyone cc'd the various I-5 cylinder heads?  If so, I'd certainly
appreciate your sharing this info with me as trying to talk the local salvage
yard into loaning me a handful of heads to disassemble, clean and measure
myself is probably an impossible task.