Well, I asked Dr. Z about 6.4L and butterfly valves and this is the answer I got:

"Thanks for contacting Dr.Z. Your message has been forwarded to us for
response.

It?s a fact; Dodge Challenger has officially received the green light
for production!!!

The Dodge Challenger concept was shown in January 2006, with great fan
fare and public response. The all-new Dodge Challenger will make its
debut as a 2008 model, in calendar-year 2008. True to both its
historical and modern concept car roots, the 2008 Dodge Challenger will
be offered as a two-door, HEMI V-8 powered, manual-transmission, and
rear-drive coupe.

DaimlerChrysler has yet to announce the pricing and product
specifications for the 2008 Dodge Challenger. We encourage you to stay
in contact with us at Dodge.com and your local Dodge dealership for
future updates.

For more information on the all new Dodge Challenger, please visit:

http://www.dodge.com/en/challenger/index.html"

Must be a standard computerized answer.