How tight are you guys running your carb to scoop clearance?

Right now I have about 6-3/4", which puts me about 3-1/4" below the hood plane.

I need to get a plenum spacer on this Indy Mod man intake, so I was thinking 2" would work.


With a 2" spacer I would be 4-3/4" from the scoop, and 1-1/4" below the hood plane still.


What have you guys ran that worked and didn't work?


Specifically this is a 62 max wedge scoop. My measurements are to the tall wide portions, not the shorter center rib.

I don't recall the measurements, but I'm at least sure the carb was below the hood surface. (360-4 Holley with 1"spacer.) I have a friend who had '65 Plymouth and corresponding scoop with the carb pan sealed to the hood. Car ran well but put up a random slower inconsistent ET with no pattern. When he cut holes/vents in the seal to the hood, the inconsistency went away. The only conclusion we could come up with was some type of turbulence within the sealed area of the carb inlet. Just another variable to consider when tuning

Either way, I believe 1" of clearance, no obstructions above the vent tops, should be enough. Same applies to an air cleaner top. I always likes the K&N Stub Stack to help smooth out flow when I was bracket racing. Carb needed 1 jet larger in my application when using one.

FWIW I was told by a reputable carb builder that 3/4" above the vent tubes is all that is required.

I have 2" from my carbs to my Super Shaker.

I wonder if there's both a minimum clearance above the vent tubes and a minimum clearance above the venturis needed to ensure sufficient airflow...

1/2" above the vent tubes is all that is needed. I've been running the car that way for over 30 years!

FWIW, I asked this because the vent tube heights can vary significantly from one carb company / builder to another, so I figured there are likely two dimensions to take into account

I have probably ran a little less than that even (use tubes on the vents to route to the valley). Car has always ran fine.

Thank you,
Casey FJ