Here is a u tube video of comperaing different cams and intakes on a 5.7 hemi. I don't remember how much. But I think the 6.4 intake lost HP/ Torque compared to the 5.7 intake. Which I couldn't beleave. I figured the 6.4 would of made more torque.
Interesting. He mentioned messing with the SRV on the 6.4 intake, but I don't find any documentation that says the Holley Dominator can control it. Terminator and Terminator X has a sub harness for SRV and VVT, but nothing for the Dominator that I find. Reading the comments, they say they controlled the SRV manually and switched over at 4000 RPM (should have been 4800 RPM). Seems like they missed something to me.
I suspect the combo had a huge factor in that, but not sure I believe that Mopar setup the 6.4 intake to be worse than the 5.7 intake. The truck intake has SRV and makes 20 HP more than the car.