GM Authority (.com) states the LNF is 9.2:1 CR. Wikipedia corroborates the 9.2:1 CR for the LNF.
LDK engines are listed as 9.2:1 CR in both places.
From everything I can locate, in multiple forums on several Ecotec web pages, a cold crank compression ratio (2-3 engine rotations) is stated as 160-175 on a 'new' (crate) engine tested with no or low miles.
A quick calculation for a 500cc cylinder that is compressing ambient air to 9.2 times atmospheric pressure results in approximately 130 psi. But this doesn't account for the dynamics of a motor or a combustible air/fuel mixture.