Based on my cylinder pressure test, I am already very close to 10:1. If each cylinder has a displacement of 412ccm2, quick math for 10:1 CR would mean a 41.2ccm2 combustion chamber, of course this is not accounting for the piston "dome" (see picture below of the piston), would further add to the CR. Image Unavailable, Please Login
Have you cc'd your heads and the dome volume as well as measured the compression height of your pistons? Gasket volume becomes part of chamber volume too. You can do all of this now that the heads are off and without doing any of the above you're guessing. All of that said I doubt you'll replace the pistons anyway but it would be nice to know.
Try GT Car Parts in Phoenix too. I bought my valves from there. Zero issues, and cheaper than Maranello.
