Tod74

I have never used a vac secondary carb either...AT least not on my stuff. I put one on my father's car but he never runs it hard at all. Just putts around.

Scooterz

KW & Tod make sense on this. I have done the opposite in my ignorant youth. Went from a correct size vac/secondary carb to a mech/double pump that was too big for the application & noted the less-than-desirable result. Smaller is better for the street in my humble opinion. I remember guys in high school who would put a huge cam in a 283 in a Impala with a power glide... with like 273 gears. They throw it in to neutral @ the stop light, drop in in gear, fan the throttle to get her moving, BOG away till about 3600 RPM's & hit a disappointing power band while blowing black smoke in the air... yeah... all for that lopey sound. I am sure that car was slower because of our "expertise." Case & point, bigger is not always more efficient.