The car in question is completely stock, but may get some stuff done as needed. Currently rocking a 1920 with twist rod throttle. I will be bolting an ancient offy 4 barrel onto it at some point. The twist rod is going away in favor of a cable setup and converting to manual trans so no kickdown considerations.

Since I will be buying/making an adapter to go from the 4bbl down to 2bbl which bolt pattern is best. I know that parts are getting iffy unless you buy brand new carter/holley units. Is the answer still to find a good unrebuilt original carb and then rebuilt it with a good kit?

The only 2bbl carbs I have sitting around in my stash are a bendix WWC from a 383(too big?), a bbd that was a parts store rebuild 25 years ago, and maybe the original motorcraft from my inlaws 69 351W mustang.

Or should find a 390 holley for the offy, that is what was on it when I got it. But that carb went away with a lot of my stash more than a decade ago.

I have been pretty happy with the 350 CFM Holley 2300 Economaster I have had on the stock slant six in my 76 D100 for the past few years.

But if you have a slant six BBD, try that first.

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Casually looking for a Clifford hyperpak intake for cheap.

If you can find a BBD in good shape, that is an amazing all around carb for a stock slant. Second choice for me would be a 500 Holley 2 bbl, but I expect the 350 would be great too. The one 350 I tried did not work well, and I never tried again.

Lou

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Home of Slant6-powered fun machines since 1988

The Holley 2300 Economaster 350 CFM carb I am running was an old stock unit I got off eBay for a good price. The previous owner couldn't get it tuned right and put it on a shelf for a long time. I got it and found the power valve had been cross-thread in the metering block, creating an internal unmetered fuel leak. Fortunately, there is a tool to repair the power valve threads, so I got one and fixed the carb. Like I say, it has been working quite well for the few years I have been running it.

It is an Economaster so it has the "wagon wheel" venturis that provide a better vacuum signal, so that might have something to do with it.

To be honest, I think the 500 CFM Carter AFB I had on the engine before the Holley worked a touch better, but got worse fuel economy. Someday I am going to disable the secondaries on the AFB and try it again as a two barrel. The primary bores on the AFB are smaller than the bores on a BBD, so it should perform OK for a near stock slant six.

With anything these days, quality and condition are a crapshoot. My carb was built in the early 2000s and then sat, unused. I don't know what new carburetor I would trust these days. I always try and find the best condition pre-2000 manufactured parts I can.

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Casually looking for a Clifford hyperpak intake for cheap.

Unless I were to trip over a juicy (new/perfect) Holley 2300 Economaster, I'd pick a 1.08-sized Motorcraft 2100/2150 with electric choke; see here (and the links it contains) amongst other threads.

The WWC3 and the 351-sized Motorcraft aren't wise choices for putting money and effort into for a Slant-6 carb.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan-

I recall looking into the Motorcraft 2100 carb years ago, but I can't remember if they have a ported vacuum source for the distributor. I have it in my head that the 2100 did not have ported vacuum advance, which is why I didn't look for one. I know they have a port under the choke for the distributor vacuum, but I can't remember if it is manifold or ported vacuum.

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Casually looking for a Clifford hyperpak intake for cheap.

I have it from Michael Ehrmann (Motorcraft 2100-2150 expert, don't know that he's still at it any more) that they all have provisions for ported spark advance.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Excellent! Glad there is another option for carburetors.

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Casually looking for a Clifford hyperpak intake for cheap.

I am partial to the 2100. That '69 one should have a 1.21 stamped on the side. I am currently running a 2150 with the 1.21 on my \6. it works fine. I am using #50 jets and a single stage power valve from a rebuild kit from Mikes Carbs.

You will need to make an adapter plate. The readily available ones for the Rochester 2gc to Holley 2300 don't work as the base plate of the Autolite is different then the Holley 2300.

The current setup on the wife's Duster is the same one as from 2007. The only difference is the 2150. My wife's old Duster got around 20mpg with a stock \6, automatic and 2.73 gears. My '65 Dart, with the exact same setup got around 24mpg with a 4 speed and 2.45 gears. This carburetor used #48 jets and a 2 stage power valve for a '75 Jeep with a 304.

I updated my wife's old Duster to an Offenhauser intake and noticed no difference from the cast iron Super Six manifold that was replaced. The only advantage is that it is lighter and has a larger hole for a carburetor.

Hmmm, makes me want to look at my inlaws carb to see if it has a tag on it. It is my father in laws first car, he bought it used around 1973 and converted it to 4bbl using OE parts back in the mid 70s but kept his originals.

I have the offy so it is just easier to use it than to get a super six unit. The offy I have has a removable 4bbl adapter on it already so converting it to 2bbl is as simple as a chunk of metal, the plasma cutter, and some time with the drill press.

Makes me curious about how BAD the numerous 2100/2150 carbs available new online are. If the castings are decent AND don't corrode in 10-15% gasohol blends it almost might be worth it to buy one and put a quality carb kit in it. I have seen new units listed at $75. Of course there are good reviews but there are also reviews stating that the units are trash.

Thanks for the replies.

I was at the in-laws house over the weekend for a party. Asked my retired father in law about what 2bbls he had laying around. He said he thinks he had 2: his original mustang carb and a variable venturi unit from a late 70s early 80 ford. I was intrigued, I wanted to see the VV carb just to see how scary it was. We couldn't find it. We did find his mustang carb, it was still bolted to a four barrel adapter that he used so that he could have a 2bbl in the winter on the 4bbl intake.

We also found a disassembled motorcraft 2100 and a complete (with tag) 2150 from a 77-79 ford truck with 351 engine. The specs say it should be a 351 cfm carb, it has the squarish lower flange, and variable air bleed system so it is definitely a 2150. It looks like it has never been apart. The only problem with it is a hole behind the air horn in the large horizontal air cleaner flange, so a dirty air leak past the filter. That should be an easy fix with duct tape while tuning and epoxy after it is verified to work. Don't want to epoxy it and then found it needs more time in the cleaner.

So it looks like I found myself a carb. It even fits the only 4bbl air cleaner I have in my stash. I believe it was off of a 76 400 newport, if it clears it will give a nice quiet intake with a mostly stock appearance.

Thanks for the suggestions.

Run away from that carburetor very fast. Be prepared to kill it with fire, twice.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

What I hear, is that the "new" Chinese knockoffs work OK for a while. Then they start to corrode. They don't have the protective coatings like the OEMs do. But that is just one of the problems of the Chinese system, they will steal your IP and and create inferior knockoffs. The Chinese 2100/2150 knockoff is a curious blend of the 2 versions. It has been reported that Autolite jets and power valves will bolt in, but they are "tight", like the threads aren't just quite right. Who knows if any of the readily available rebuild kits will work.

But then you also take a chance with a 50 year old core too. The carburetor cleaners are not as good as they used to be. So it takes a while to just "clean" them. There may be hidden cracks and other unknowns. I spent a lot of time and energy rebuilding a 2150 to find out it had "cracks" in the idle circuits. I pulled one out of my box of cores and it just worked. Go figure.

Worn original and crap new/reman two barrel carbs are why I advocate getting a new small four barrel and disabling the secondaries. It would be tuneable like a four barrel but only flow like a two barrel.

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Casually looking for a Clifford hyperpak intake for cheap.

LOL if i had found that carb in his stash I would make sure to take good pictures of it for you. You should get one and make it actually work as intended to prove your greatness/knowledge.

Come on take on the expert challenge of fixing trash that never worked when new, after 40+ years that carb still sparks fear in the hearts of anyone that fixes cars.


I have been thinking of that option. I just wish that holley/edelbrock would include the CFM rating of the primaries and secondary separately. A square bore 600/650 would likely work just fine on just the primaries.