To quench or no quench

The more airflow available...the more chance of it rattling.
So just keep in mind that if you feel you are on the edge compression wise already... putting a high flow in head on there is going to fill it even more. You end up with the actual being more than it shows on paper.
I havent read what cc the x heads are..
But a 600 carb WILL have a restrictor plate effect on this combo and help fight against pinging. Lol
541sd .054 thick, I think, that would leave you plenty and the heads can be 68-72cc who knows.. you surely wont be hitting the heads