recipe for 11.5:1 compression
 

Is there a way to do this with milling the stock heads and not having to worry about ptv clearance on a stock piston and a cc306 with a 1.6 rocker?

Yes................

Yes. Running a stock block with milled heads and a cam more aggressive than the 306. No clearance issues.

How much does the head need to be milled using a .026" head gasket?

about .030" if your block hasn't been decked.
be prepared to do some machining on the intake manifold ends and slotting the holes to seal and match the intake ports.

I really wouldn't suggest taking that much off the heads..The intake valve will be right at the deck of the head....and if you need to mill them again you will have to move the seat back or you will be cutting into it. Just my 2 cents though

Oh, I agree. He asked the question. If it were mine, I'd avoid taking that much off.

I know and I wasn't criticizing you...just throwing it out there if he didn't know

I agree guys. Maybe taking .020" off and a .026" head gasket will be sufficiant enough. Just want to bump the compression up a little to gain that little extra power.