I have a mildly hopped up Model A and I was going to run a Holley 94 on it. My question....If I ran a three carb intake with only the center carb running will it work just like having a single carb intake?
That will depend on the runner design of the intake. Most guys will close off the center carb and run the two outer ones to provide more even distribution. What is the make of the intake? What engine?
I haven't bought the intake yet but the motor is a Model A, counterbalanced crank, "B" cam and waiting to get my 7.1 head
Be aware that if both of these are active you will need to swap out the power valves for ones. Stock ones generally have a 7.5-in-Hg. valve. For multiples the general rule is to install ones that are even divisors of the 7.5 originals. A good start for duals on a small engine with 94's, would be a 3.5-in-Hg. valve in each. If you did three, you'd need 2.5's in each, and likely a progressive linkage that brings in the other two late, and only allows them to open 30-40%. https://www.carburetor-parts.com/holley-94-power-valves They are only about $13/ea. and make a HUGE difference in multi-carb performance.