Rich's 5/9/408 build used similar pistons, the Trick Flow heads and he was told with the .040 Cometic gaskets, he is expected to be at 10.6 to 1.
That should be fine given the camshaft he is using. That stick is in the high 230s of .050 duration and just shy of .580 lift.
The pistons are labeled as zero deck but we didn't measure and the heads are torqued down now. The cam spec's are 238 /242 @ .050" and .576 / .587 lift with 1.6 rockers.
The 440 in the Coronet has Stealth heads with a hyd FT cam specs of 234/238 @ .050" and .550 lift @ 1.5. The timing is 33° (19° initial + 14° mech) and doesn't detonate, although when it was first built with 35° total it would ping so I had to back off the mech 2°. Just came back from a 960 mile round trip to Spring Fling with no issues. I'm running 91 octane pump gas.