Author Topic: What is this square "box" for?  (Read 607 times)

Offline spoolboy

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What is this square "box" for?
« on: April 03, 2025, 10:31:32 AM »
I haven't seen this on other images of carbs. What does this "box" do? The rear booster tube sits into it. But it's only on the passenger's side.

Offline novadude

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Re: What is this square "box" for?
« Reply #1 on: April 04, 2025, 08:37:11 AM »
I think that was unique to Chevrolet 1965-1969 carburetors (maybe just small block?).  I believe it was added to address mixture distribution on the "high" side of the dual plane manifold.  Maybe others can provide more info.

Offline spoolboy

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Re: What is this square "box" for?
« Reply #2 on: April 04, 2025, 09:33:42 AM »
This QJ is off of an 86 Dodge truck. I have 2 of them that are identical - 17085408.

I think I saw someone say it was a stop for the air door somewhere, but I made the door adjustable and it doesn't contact it even when fully open.

Offline 77cruiser

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Re: What is this square "box" for?
« Reply #3 on: April 04, 2025, 10:51:55 AM »
I think that was unique to Chevrolet 1965-1969 carburetors (maybe just small block?).  I believe it was added to address mixture distribution on the "high" side of the dual plane manifold.  Maybe others can provide more info.

I've heard it was about mixture distribution too but I don't know what all they were on. I've only seen 2 I think & they were on early carbs.
Jim