Quote: stock head gaskets 04 - 08 engines about 9.5 to 1
09 heads on an 04-08 = 12:1 with stock gasket
with a .050 gasket is close to 11.5 to 1
dont quote me on exact numbers but these are close.
you probably would not want to use a stock gasket without adding a extra shim, a stock gasket with a shim will give about .040 piston to head clearance