notched pistons questions

hey, hows it going, i have a 1985 mustang gt 302 h.o roller engine, im thinking on new heads (edelbrock performer) but i had my engine rebuilt a few years ago and the builder put in just flat tops with no valve relifs. i know my engine did come with forged notched pistons but i dont know what specs are on them.

how many cc's cut into the piston do u use on a set of aluminum heads? also my engine is now a 306ci, so now i need to know a whole bunch of things. like how many mm is a .30over piston? also what is the bore and stroke of my engine now? feel free to add to these questions cause im totally lost when it comes to this. thanks alot.

so the 3 inch stroke would stay the same no matter what u did to the engine with the stock crank and rods?

is the the stock (standard) bore of a 5.0, 4.030?

with my 5.0 bored .30 over, would the bore be larger than 4.030?

nope, pistons are just flat tops, no valve relifs in them.

the heads are 1.90 / 1.60 valves.

also wondering is why ford put in valve relif pistons because i guess there not needed cause the engine builder put in just plain flat tops, and put in a bigger cam (dont know the specs) and did a 3 angle valve job to the heads. thanks alot.