340 stroker 422

That’s probably going to be some way out. I can work on the chambers but it’s not going to make that much of a difference.
Purpose of this is to make good power and torque on the street.
Also engine needs to make good vacuum for power brakes.
It will make more of of difference than you think, if done right. The chamber has a lot to do with detonation.
Did use use the 0.039 x 4.180" head gasket in your calculation or the 0.039 x 4.04".