Of the 3 heads in the title, I have two of them. But not on 408’s.
I have the Edelbrock’s & the ProMaxx CNC Shockers which are Edelbrock knock offs and only a 5cc difference on the intake port, which do flow pretty good. The CNC porting isn’t a full tilt job. For anybody wondering, here is the Pro Maxx page in the head. Just scroll down and click the flow sheet bar. I’d call it a good bang for the buck up until the new Trick Flow heads. Except for the added cost of the rocker set up for the Trick Flow heads, in which if you already have a roller rocker set up that works on the Pro Maxx/Edelbrock head, the Trick Flow, it is a win win.
Since your not lifting the valve to .700, the only lifts that count is how high you actually are lifting the valve. (Net or actual at the valve lift.)
