400 budget compression HELP +++++

IQ52. Well, when working with a slug deep in the hole, quench is out of the question. Rebuilding it may not be an option. (It isn't for me) Airflow trumps compression for adding power correct? Adding a cam helps unless the compression ratio is in the bottom of the bowl. I don't think going from a open chambered OE head to a closed chambered aftermarket head would hurt or push anything to far.

How do you help a low compression 400 beyond your thread? Just wondering?