349cui build up

I have looked into this same bottom end scenario using a 360 stroke and 318 truck slug cast piston, and it works just fine. I had 65cc chambers, and with about 0.013" above the deck, corrected with slightly thicker gasket, my CR was right at 9.7:1.

And unless you are spinning that engine frequently over 6600, I doubt the cast pistons would complain.