[elefantrider]

I am having an annoying issue with stumbling/hesitation on the center carb when accelerating. It only happens when driving, not when free-reving.

Hoping for an easy fix without drilling out the carb if possible.
The car will start on the key, the first turn, and idles great.

Is there a way to increase or decrease the pump shot without drilling out the tubes?
I am surprised this 455 carb wouldn't already have enough shot for this smaller motor.

Anything else come to mind?

Center Carb: Original 455 2bbl NOS rebuilt, stock jetting - untouched, jets 61?
End Carbs: Stock '65, bores opened up on a machine, jets 74

Here is the rest of my combo
433CI
11:1 compression
Ross flattop pistons .005 in hole.
Ported #77 '65 389 heads, Ported intake
230-236 HR Extreme energy on 110 LS, 1.6 rockers
4 speed, 3.73 gears.
Distributor has 8 initial and 34 total timing, in by 3000. Vaccum advance limited to 6 degrees.
Full exhaust.