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What Carburetor for Factory 4-bbl?

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javelinjason View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote javelinjason Quote  Post ReplyReply Direct Link To This Post Topic: What Carburetor for Factory 4-bbl?
    Posted: Feb/10/2020 at 10:29am
Pardon my ignorance, but what aftermarket carburetors will bolt up to the 73 factory four barrel intake, without modification? Not sure I want to keep the Motorcraft carb on my 73 AMX. Also, does anyone have a source for the carburetor insulator/spacer? Mine was shot and I can't seem to find a replacement. I looked at the Trans Dapt carb spacers, but not sure which part number would work. 
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Heavy 488 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 10:39am
I believe that is still the 4300 and not the later 4350 spread bore. In that case a Carter, summit or Holley bolts on.NAPA may list the original style insulator.
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javelinjason View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote javelinjason Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 10:48am
The intake is the 3217486 4bbl from the 73 AMX on the 360. 
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Heavy 488 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 10:55am
It's more than likely a 4300 that uses a more common footprint. I believe the 4350 came in later in the 70's. You can easily check images of 4300 or 4350 online and compare which model it resembles.


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Sonic Silver View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 3:40pm
Originally posted by javelinjason javelinjason wrote:

Pardon my ignorance, but what aftermarket carburetors will bolt up to the 73 factory four barrel intake, without modification? Not sure I want to keep the Motorcraft carb on my 73 AMX. Also, does anyone have a source for the carburetor insulator/spacer? Mine was shot and I can't seem to find a replacement. I looked at the Trans Dapt carb spacers, but not sure which part number would work. 
Any square bore carburetor will fit.

Edit: I was thinking that I should clarify the above. Some of the bigger cfm carbs have primary throttle butterflies that may be too big to open over the front 2 holes in the stock intake. I think the holes may be 1-7/16 inch in the front and 1-9/16 in the back. I believe that most, if not all 600 cfm square bore carbs should work. A spacer should fix the problem.

Edited by Sonic Silver - Feb/10/2020 at 8:08pm
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White70JavelinSST View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote White70JavelinSST Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 4:29pm
I have a 401 out of a 76 Grand Wagoneer, it has the spread bore setup. Not sure what year it started.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BassBoat Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 5:27pm
Trans-dapt makes an adapter for the weird motorcraft spread bore used in mid 70's jeeps and most ford 460 applications.  Inch thick aluminum from spread bore to square bore holley pattern'
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FSJunkie View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Feb/10/2020 at 11:58pm
I have a 1973 360.

The stock carburetor is a Motorcraft 4300. It is square bore. The secondary barrels are a little larger and higher flow than the primary barrels, but it is still a standard square bore gasket and bolt pattern. The manifold is a standard square bore manifold.

The 4350 is a spread bore unique from the Quadrajet. It may share a pattern with the Thermoquad, but I am not sure. The 4350 was introduced in 1974 or 1975.

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AlexK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AlexK Quote  Post ReplyReply Direct Link To This Post Posted: Feb/11/2020 at 2:18am
The 4350 was introduced in 1974, might be late 1973.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Feb/11/2020 at 5:33am
4350 introduced in '75.
Nothing wrong with a properly rebuilt 4300. RamairRick does a professional job on them.


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