670 vacuum secondary vs 650 double pumper

What would be the difference going from a holley 670 street avenger carb to a 650 double pumper. Would a larger double pumper be better? Let me know what you think. This is a street car 99% of the time and not a daily driver.

Combo:
340
Big valve J heads
Roller rockers
Eddie air gap intake
Lunati 268 voodoo cam
Hooker headers
4 speed
3.91 gears