I'm wondering if this combo will work on pump gas?
MP advertises these heads as 58cc.
To get the piston to deck clearance of those KB's, it goes like this;
Deck height (9.6") - sum of half stroke distance (3.58"/2=1.79") + rod length (6.123") + compression distance (a KB 107 is @ 1.675") which leaves you with .002", which is the distance from the top of the piston to deck. If you've milled the block .002", you have effectively given the engine zero deck on these pistons.
The KB 107 has +5cc for valves.
Add a .040" gasket, which is now all of your quench distance and you get 11.47:1 static comp ratio. In Washington, altitude is 1,706' avg. Your dynamic compression is going to be up there, even at zero on the cam advance.
If I were you, I would be checking everything with a microscope. CC those heads in real life and see exactly what they are, with the plugs in that you plan on using. Check installed height on those pistons with a mic and see what they actually look like.
As stated above, unless you are up in the mid 60's on the heads, this is a lot of comp for a street engine, even with a mild cam.
What are you planning on doing with this engine?