Need advice on my 318

i've got a couple thoughts or questions
1. what if you used the stock pistons and used 302 casting heads slightly milled, where would that land your CR
2. what if you bored the block .030 used factory type pistons and used the factory heads milled CR?
3. bored .030 with stock type pistons and 302 castings milled or not?
don't wanna mill too much though cause of alignment issues.