Changing compression ratio

[turboSlap]

Ok, im getting ready for a clutch upgrade(fx400) and I have acquired some AMU pistons and a block for building. My plan is to have those pistons and upgraded rods into this block and have it ready to swap out with my original AEB engine while doing the clutch. After a few thousand miles when I've broken in the clutch and engine and got my emissions out of the way( late this year) I will be going ahead with the turbo side of things.
My question is this: when I go and swap out the original AEB pistons(9.5cr) for AMU (9.0) will the car run at all on just a plain old GIAC ecu??? Will I need to add fuel to get it to idle/run ok?? Would an adjustable FPR work?? Or am I asking for trouble??

[GTijoejoe]

half a point, it'll make basically no difference....

[turboSlap]

So I won't have ANY problems with starting, running or idle??i really can't afford to have problems with it after its all back together as its my daily.

[TBT-Syncro]

no need to do any mods/changes. the .5 compression is trivial