my slant buildup

IDK if anyone out there is following this, (I did say early on that I was doing this largely for my records and a place to "look back on") but project creep is showing its ugly head again//// Now that I found out (and am disappointed by) that, even after a 30-thou block deck shave, my pistons still wound up that far in the hole, at TDC even after the shave.....
All along, I have been kicking around the idea of doing a draw thru turbo.... I went by the machine shop yesterday to check progress on the head... and they asked if I had a "number" to mill off the head yet. I told him I need at least 1-2 chambers CCd before I can tell him.... at this point I'm again wondering if I should.....or stay the course, and build the strongest NA motor I can that will run on pump 87?
Has anyone here, CCd a stock #447 casting combustion chamber? What do they run, unmilled? Anybody? (please don't give me links to places to figure out CR... I got a few of those from people already.... I don't yet have the number to fill in the blank for "starting combustion chamber CCs")