You would need all of the variables in order to calculate the CR, but I suspect it might be close to 9.5:-10.0:1.
In boosted engines, you're always at odds with dynamic pressure and the onset of detonation. In general, you can make more power ultimately, with a lower ratio and more boost, but as Mike indicated, also at the expense of boost response.
One of the reasons you don't see 3.820" turbo pistons, is that the cylinder walls start to flex when they are bored over .020". I personally would not build a turbo motor with a .040" over bore, unless I were using one of the Racing SVO blocks.
Honestly, you'd be better off to find an un-bored junkyard block and having it machined.
TVS Supercharged SVO 2.7L
561 ft lb