What is the c.r. on a 6.0 bored .030 over, stock 6.0 heads, stock crank, -30cc pistons and mls head gaskets.

 

Here is the site you need.

http://www.rbracing-rsr.com/compstaticcalc.html

 

LOW.
With a .054 gasket and a -.007 deck height you get a whopping 7.77:1
With a .040 gasket you have 7.95:1
Mill the heads to 66cc's and run a .040 gasket and you get 8.35:1
I cant see a good combo without switching heads.
You would need a 60cc head and a .040 gasket to get you back to normal FI compression at 8.8:1