As George says There Are "Better" heads out there vs the E-Heads, I think Don's heads being one of them, High Ports being another, CV-x heads, Tiger Heads, Visner heads, even Larry's old heads. They all have more flow area vs the old Non wide Port E-Heads.
And Boosted Engines like flow area, be it from big single ports or from 4 Valve type heads.
When a 5.0L Coyote engine with 4 valve heads can make 1400 RWHP it is not in the displacement, it is from the flow area of the port and the boost pressure.
Melissa Urist’s Hellion-boosted GT is the most powerful street S550 around
https://www.svtperformance.com/2016/...-2015-mustang/
The engine does not care whose name is on it, it does care how the engine breathes and what it sees for mass flow thru the cylinders.
Which is why George WILL be in the 7s when he gets his larger supercharger.
Chief will go fast with the new heads as they have more flow area, not because they are canted valve (but that does help somewhat with a smaller bore size engine.
50 psi of boost is another reason why his 482 engine runs well, and in the 3s.
Tom V.