Motorcraft/Autolite 4300?

[JC Mustang]

Wow, it's been a long time since I've posted here...brings back memories. I'm getting back into my Mustang after a long layoff because I finally have free time (!) and hopefully a little money, so it's good to see some things never change (2bav8 still moderating, I saw a mustangdave post).

A friend of mine gave me a carburetor, that I believe he said came off a '69 351 (I can't remember if it was Windsor or Cleveland, I know he had one in his car and one lying around). It definitely looks exactly like the Autolite 4300 from the Pony Carbs page (apart from the missing choke cap or whatever you would call it), but I have also heard reference to the Motorcraft 4300, and there is no identification on it that I can see. Is it the same thing? I would ask my friend about it, but I have fallen out of contact with him.

Now, assuming this is the carburetor, is this carb too much for an otherwise stock 289 (I've got an Edelbrock Performer to go with it)?

 

[Mil1ion]

Maybe it's a 4100 ?

Carburetor Restoration, Rebuild Kits, Floats, Chokes and Parts for Cars, Trucks, Industrial and Marine - The Carburetor Doctor

 

[JC Mustang]

Maybe it's a 4100 ?

Nope, that one looks almost exactly like my 2100, except four barrel. The accelerator pump on the new one is on top like the 4300 picture on Pony Carbs. I guess that's what it has to be...

 

[stonecoldtx]

Wow, it's been a long time since I've posted here...brings back memories. I'm getting back into my Mustang after a long layoff because I finally have free time (!) and hopefully a little money, so it's good to see some things never change (2bav8 still moderating, I saw a mustangdave post).

A friend of mine gave me a carburetor, that I believe he said came off a '69 351 (I can't remember if it was Windsor or Cleveland, I know he had one in his car and one lying around). It definitely looks exactly like the Autolite 4300 from the Pony Carbs page (apart from the missing choke cap or whatever you would call it), but I have also heard reference to the Motorcraft 4300, and there is no identification on it that I can see. Is it the same thing? I would ask my friend about it, but I have fallen out of contact with him.

Now, assuming this is the carburetor, is this carb too much for an otherwise stock 289 (I've got an Edelbrock Performer to go with it)?

If I remember correctly, there were about three different sizes of 4300 series carbs--a 600CFM (used on the original 302's in 68, and I believe the 351W's in '69), a 630-650 CFM (used on some of the later 351C's) and a 750CFM spread bore that was mostly used on the big block engines (sometimes you might find them on some 351C's, but they were mostly installed on 460's).

If it's off of a '69, it's most likely the 600CFM unit, it would have been on a 351W (351C's weren't made until the '70 model year) which should be just fine for an otherwise stock 289.

 

[JC Mustang]

If I remember correctly, there were about three different sizes of 4300 series carbs--a 600CFM (used on the original 302's in 68, and I believe the 351W's in '69), a 630-650 CFM (used on some of the later 351C's) and a 750CFM spread bore that was mostly used on the big block engines (sometimes you might find them on some 351C's, but they were mostly installed on 460's).

If it's off of a '69, it's most likely the 600CFM unit, it would have been on a 351W (351C's weren't made until the '70 model year) which should be just fine for an otherwise stock 289.

Cool, thanks for the helpful info. Now, another question, is the tube coming out the back of the throttle body for the PCV, or will I have to get a 4bbl spacer for that?

 

[stonecoldtx]

Cool, thanks for the helpful info. Now, another question, is the tube coming out the back of the throttle body for the PCV, or will I have to get a 4bbl spacer for that?

To be honest, I really don't remember--it's been nearly 30 years since I even fooled with one . . .

If it's a vacuum source, you could put a PCV valve there, or connect it to a vacuum tree in the event you have other things that require vacuum, such as a power brake booster, a/c vents,etc.

Either way, I'd recommend using a spacer anyway, because that helps isolate the carb from the engine heat.