D,
When I ran the SC14 on an A14, it made max boost instantly. No down low miss, no hesitation. Just lots of traction problems.
I wouldn't worry about low down response issues with the larger pump.
I wouldnt use a dashpot style Variable main jet carb on a supercharged motor. When I ran the weber, it used to make 5psi on the primary, and 11psi (I think) with both holes open. The further the throttle is open, the more boost it made. Having to wait for the dash pot to rise would cramp my style. I think you'd get better response and control with a conventional type carb. I
I still have the weber, air filter, and the SC carb adapter in the above pics if you were interested?
I Might add that the 11psi figure above was running an N/A performance cam which had too narrow a lobe seperation angle, so some boost might have been bled off. When I ran an A14 with a Stock cam, it made around 1 bar. Which is too much without some additional detonation control measures. (see pic of smashed piston in my album)
I'm still running the clutch pulley too. I've not pulled it apart yet, but I've heard it's a bit of a challenge to delete the clutch set up. I can get you a very sharp price for a custom three piece crank pulley to suit the Toyota blower pulley. Being three piece you can change the ratio of the crank or blower drive pulleys with ease.