340 or 318 turbo

I would say yes.
Normally the bigger heads rape the compression ratio, and make a soggy engine even soggier. BUT when you've got a pump cramming it down it's throat, that don't matter none. The bigger chambers help make the compression ratio more boost friendly. And the larger ports reduce the restriction the pressure fed charge encounters on it's path into the cylinders. This can mean a lower boost figure, but with more charge actually finding it's way into the cylinders. As it's compressed less, it'll typically heat up less. So it'll be more dense too.