Just double checking 10.5:1 compression recipe for Predator 212

[cpu77]

I am trying to decide if I should get my head milled. I already have +.20 Rod which brings piston flat with stock head gasket. Is having the head milled worth it? I want to run 87 octane with 10.5:1 compression.... How much should I take off .30-.50? I am new to all this so please excuse my ignorance

My setup is
Black Mamba Jr Cam
Billet +.20
Billet Flywheel
26lb Springs
Stock Stainless Valve
Intake/Exhaust
11t/60t
TAV 30

Thanks Guys!