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500 cfm center carb?

JRL

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hi,
Have seen some put on a 500cfm center carb on their six packs. Can anyone tell me what carb to use?
 
It is a Ford carb. Sorry, that's all I got.
Make note to the fuel Inlet position. Driverside
 
The first six pak I bought had a 500 2 bbl center carb & '69 end carbs. It was the standard 500 at the time, early 70's forget the number. The setup used mechanical linkage for the end carbs. I ran it that way a few times, then we decided to drill a port into the venturi & convert to a stock style system. That worked great. The 500 probably was a good deal. If you setup the vacumn for the end carbs & tune the springs, it works pretty good.The jets seemed to like being close to stock in my application. And I had a high compression, big (at the time) cam. However I did go to a stock '70 carb setup. They worked really well. For some reason the '70 carbs were a bit smoother. Again very little jet changes done to them.
 
I've wondered about that myself. IF you can use a Ford (Holley) carburetor, then you can definitely swap out the fuel bowl to put the fuel inlet on the passenger side like the other carbs. My idea was to get 500cfm Holley of an old (say '73'ish) 360 2bbl. and hacksaw off the back of the carb/air cleaner part that isn't used (so I get a "D" shape that fits a six pack air cleaner)
 
My first setup with the 500 center carb had the back half of the carb mount cut off to match the stock six pak configuration. It fit just fine with the OEM '69 air cleaner setup. I can see lots of grinding was needed.
 
So If you've got the right ford carb, you can just swap fuel bowl and metering plate from the stock center carb?
 
I'm not sure but it is a Holley and probably very interchangeable with each other. I just "Don't know" for sure.
 
My first setup with the 500 center carb had the back half of the carb mount cut off to match the stock six pak configuration. It fit just fine with the OEM '69 air cleaner setup. I can see lots of grinding was needed.
I've been running one on my RR for years. Bought the 500 new and cut the air cleaner ring to match the two bbl Holleys. You have to use the linkage from an original six pack center carb. I had an old, modified one that wasn't working very well. There are some differences, and my center carb uses quite a bit more jet than a stock six pack. I used the 500 out of cheapness...it was about $250 less than a center six bbl. I can check jet sizes if anyone cares.
 
So If you've got the right ford carb, you can just swap fuel bowl and metering plate from the stock center carb?

Not exactly.... and it doesn't have anything to do with "Ford" but it has everything to do with "Holley".
1. You can get OEM 500cfm Holley 2-barrels on Fords, Mopars and others too....Chevy, Pontiac?
2. I don't think that how the passages of a Holley main body match up with passages on metering bodies are "universal", but I'm not positive on that. I'm not sure if you can "mix & match" parts like that.
3. The main issues I see with a 500 cfm center carburetor are:
a. how linkage connects with outboard carburetors
b. the "D" shape of six pack throats. I think Fords are the same and Chevies have a slight "V" shape on the flat part of the "D".

Here's a question..... The baseplate of the center Mopar six pack carburetor has smaller "butterflies" than the outboard carbs. Is there a way to swap out JUST the baseplate & get 500 cfm or is the venturi of the center carburetor what limits it to 325 cfm?
 
Not exactly.... and it doesn't have anything to do with "Ford" but it has everything to do with "Holley".
1. You can get OEM 500cfm Holley 2-barrels on Fords, Mopars and others too....Chevy, Pontiac?
2. I don't think that how the passages of a Holley main body match up with passages on metering bodies are "universal", but I'm not positive on that. I'm not sure if you can "mix & match" parts like that.
3. The main issues I see with a 500 cfm center carburetor are:
a. how linkage connects with outboard carburetors
b. the "D" shape of six pack throats. I think Fords are the same and Chevies have a slight "V" shape on the flat part of the "D".

Here's a question..... The baseplate of the center Mopar six pack carburetor has smaller "butterflies" than the outboard carbs. Is there a way to swap out JUST the baseplate & get 500 cfm or is the venturi of the center carburetor what limits it to 325 cfm?
Here are some photos of the 500 on my car. I did not do the modifications. They were done by a friend of mine.
Pass Side With Grinding Marks.JPG
Rear Ground Off.JPG
Throttle Linkage.JPG
 
is there enough material to fit a threaded tube in the venturi?
 
I'd be interested in knowing more about that center carb Frustration. I think it's my never-ending search for more speed
 
I'd be interested in knowing more about that center carb Frustration. I think it's my never-ending search for more speed
I'm not so sure it will give you more performance than a stock setup. As mentioned, I did it to be a bit thrifty. A six pack setup only works if it all works together. I've been told that the stock intake will only flow so much. I know stock eliminator cars that are running bottom 10's with a stock set up, including the intake, heads and stock valve size. Mine has only gone low 11's on another engine. Below are the post-fire photos I mentioned above. Thank God Tommy was there with his fire extinguisher!!
IMG_2618.JPG
I'm sure there's more in mine, as I'm an amateur tuner. That being said, how can I help?
 
If you drill a hole in the side of the body/venturi, is there enough material in the wall to tap threads?
 
If you drill a hole in the side of the body/venturi, is there enough material in the wall to tap threads?
I honestly can't remember. If you're thinking about the vacuum hose barb that goes into the side of the body, I'm pretty sure we JB welded a tube into the side of the body. The biggest problem I had was with the hose for the PCV valve. It comes off the bottom/back of the carb. I used a 90 degree fitting, but needed to modify that as well to make the turn without hitting my rear carb bowls. Just had the car out for a ride. It drives great. No issues whatsoever. When the outboard carbs come in...it's a beautiful thing. HAPPY NEW YEAR to all!!
 
I just drilled a hole through the body into the venturi that was the proper size for a press fit for a 1/8" brake line. Worked great.
 
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