Sorry for the confusion with my last WTB post. From what I am told I looking for a Autolite 4300-A carburetor. My car is a M coded 1971 Mach 1 with original 351 Cleveland 4 barrel car. It has the original cast iron manifold and 4 speed. Built 7/71. Mostly original except for the paint and steering wheel. This isn’t a show car but a very nice driver. The correct dated carburetor would be nice, but not necessary. I’m looking for a rebuilt or good core that can be rebuilt. Thanks to everyone for there input and setting me straight. Please PM me if you have one. Thanks
Hi
I thought all 1971 and up Mustangs with 4v Clevelands had a Spreadbore Intake and the factory carb was a 4300D, 715 CFM spread-bore (manufactured from 1971-1974).
With that said, I have a 1973 H-code - 2v Cleveland and I wanted to replace it with a 4v and have it look completely stock. After some research, I went with a 4300A, 600 CFM (1968-1974). I stayed away from the 441 CFM version of the 4300A due to its limited flow, and opted for a 600 CFM version of the same released in 1968.
I have mine professionally rebuilt, and it has been very reliable, and my mildly modified Cleveland with Aussie heads, Dished Pistons, and an Edelbrock Performer Intake work well together. I think the 441 CFM would be too small on anything but a bone stock 2v Cleveland, but the 600 CFM is plenty for a street car. It has been very reliable from my experience over the past 6 years, I have no complaints.
4300A General Criticism...
Both variants of the 4300 have been criticized for poor acceleration, rough operation, and a potential for fire due to a poor fuel inlet design. This negative reputation is not universally accepted amongst users of these carburetors.
For what it's worth, here are details on the 4300 Carbs - A 441 CFM & 600 CFM (Squarebore), and the 4300D 715 CFM Spreadbore.
The Autolite-Motorcraft 4300 carburetor
4300A, 441 CFM (1967-1969)
The first version of this carburetor was released in 1967, replacing the 4100 on all Fords excluding the police package 428 CID and 289 CID high-output engines.
4300A 441 CFM specs:
1" primary venturi
Primary throttle bore: 1-7/16"
Secondary throttle bore: 1-9/16"
The 441 CFM carburetor was found to run too lean for the 390 CID engines; hence, the 600 CFM 4300A was developed the following year for these larger applications. The 441 CFM 4300A was discontinued after the 1969 model year in favor of the two-barrel
Autolite 2100 carburetor.
4300A, 600 CFM (1968-1974)
Due to the limited flow of the 441 CFM version of the 4300A, a 600 CFM version of the same was released in 1968. By 1970, it was factory supplied on most Fords equipped with a big block 429 and 460, in addition to some vehicles with a 351 Cleveland.
4300A 600 CFM specs:
1.25" primary venturi
Primary throttle bore: 1-9/16"
Secondary throttle bore: 1-11/16"
4300D, 715 CFM spread-bore (1971-1974)
In 1971, a much more pronounced spread-bore design was released, dubbed the 4300D. They are incompatible with other spread-bore intake designs.
4300D 715 CFM specs:
1.25" primary venturi
Primary throttle bore: 1-9/16"
Secondary throttle bore: 2"
Motorcraft 4350
The 4300D was replaced by the
Motorcraft 4350 carburetor in 1975.
