6 Pack vs. 650 4BBL?

No way will I say the 6 pack out runs a "good" 650 on your LD340. What 650? You might even see an improvement if you go to a 750 double pumper on top that intake.
Very rarely do u see a 6 pack on a street car faster than 11's, and how many do u see in the 9's? Just say'n
Sorry it is a Holley 600 -
Holley 4160 Adjustable Float Carburetors 0-80457S