Compression on LS2 with 317's?
 

Stock height heads and .050 turbo gaskets on an LS2, stock bottom end. Anyone know the compression?

I'm guessing about the same as an lq9 around 10.2. You should google compression calculator to verify though.

A vendor did some testing some time ago where they CNC'd 243s and 317s then milled the 317s to the same chamber size and the 243s were like 20hp up on the 317s due to the better chamber.

I understand you are trying to lower compression for boost but I am questioning whether the less efficient chamber is worth it.

Very good points where quench combined with chamber efficiency help NA
apps make more torque with less timing. However none of that seems to
matter in boosted apps where the cylinder pressures escalate exponentially
from cramming several atmospheres through it. I've recently seen a trend
with heavy nitrous guys and big boost guys running super thick head gaskets
and/or running the pistons down in the hole in order to lessen the effects
from quench to aid longevity...ring lands etc.