Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Dialing in your rebuilt Quadrajet carburetor => Topic started by: spoolboy on April 03, 2025, 10:31:32 AM

Title: What is this square "box" for?
Post by: spoolboy 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.

Title: Re: What is this square "box" for?
Post by: novadude 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.

Title: Re: What is this square "box" for?
Post by: spoolboy 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.

Title: Re: What is this square "box" for?
Post by: 77cruiser on April 04, 2025, 10:51:55 AM

Quote from: novadude 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.

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.

Title: Re: What is this square "box" for?
Post by: novadude on April 07, 2025, 05:53:32 AM

Quote from: spoolboy 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.

Interesting.  I've only seen them on the early carbs.