Takes a lot of time.
Like everything mopar, the potential is there if you know what you are doing.
Those / heads dont gain **** more than 20 cfm without spending the time.
It's the floor, and that's what everyone shys away from.
I have a few heads.
/ big valve head ported 195-200cfm is what I get. I'm not trying to set the world on fire, but its respectable. Most of that is under .400...the last 10cfm is .500-.550 and hanging on.