[BB427]

Zimmy,
I know the 120s are the standard holder and I have questioned this with my carb builder. He (Mike @ pierce)told me the smaller holder is the reason I have no hesitation or pop at the transition between the two circuits around 2500-3000 rpm. (A trick they have learned over the years)
I have thought of that and I may try it if I can't get a handle on it.

Thanks
Brent