Hey guys,

I'm putting together a super six setup on my 1980 Dodge d150 and just needed a little information.
I know the carbs that were used on the Super Six were the Carter BBD and the Holley 2280, which were both 318 carbs, right?

So whenever I find one for sale, it is of course listed as a 318 carburetor. Are there any differences between the carb for the 318 and the 225? I think I read somewhere that the choke linkage or something like that was different but could be modified to work.

Basically I'm wondering if I'll have any troubles running a BBD or 2280 listed for a 318 on my six.
Any input would be awesome

Thanks guys!

I don't recall any of the BBD carbs I have worked with not properly fitting a slant with a thermostatic choke. the pull off that bolts into the pocket in the exhaust manifold is different but I don't consider that piece part of the carb its self. I do believe that the jetting is different between the two but that is a normal part of tuning and they aren't off far enough to not run reasonably.

There are both internal end external differences between the 225 bbd and the 318 bbd. First, read the Super Six conversion article HERE. Then read the bbd operation and repair manual linked HERE. i actually have a 1976 Chrysler training manual that covers the differences between the 318 and the 225 bbd.

Most sellers won't know the difference between the slant and the v-8 bbds, so they just call every bbd a 318 bbd.

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Casually looking for a Clifford hyperpak intake for cheap.

The 83 d 150 I have already had the carb swapped to a non-computer BBD. When I went to rebuild it the kit for a 318 was the only one that was right.What your going to have problems with is the choke if you want to keep the automatic choke .The choke stat and arm have to be modified,I have a manual conversion and the easiest way to set it up is to run the cable forward and wrap it back into the cab-which leave problem 2-it now works backward,in is choke on and out if off, As far as the jets ,the metering rods are fully adjustable, I lowered the float a bit-lowered the metering rods and limited the step up on the power valve to less then spec.For the most part runs pretty good. You need to play with the adjustments.First trip I made the quarter panel looked like it was from a diesel,then around town the plugs would carbon foul.Go it to where I know its a bit rich in main metering from how it runs with the choke off when cool-but thats all and never got bad gas mileage out of it.

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I may be slow,but I"m ahead of you.

The question regarding the differences between Carter BBDs made for 318 V8s vs. those made for the SlantSix, frequently pops up, so I have extracted from the BBD manual the pages specifically related to the slantsix version of the BBD that appeared on the SuperSix engine in 1977.

You should read the entire manual before making adjustments/repairs, you will find a link to the whole BBD manual in Reed's post above.

BBD_slantsix_differences.pdf

Feel freee to make a copy.

Olaf

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Aspenized

"Zilla said the super six actually ran rich on a dyno.

I know the idle circuits are different where the adjustment screws go. One of these days I will do a photo comparison and post it.

Thanks for the link Olaf!

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Right now the carb is slightly lean ( when cold) under load (manual trans )between 900 and 1500,and that's only because its tweaked to that point.And yes-the idle circuit had something addition added to that BBD for the six-but I believe it was added as a fix for emissions lean down drive ability issues when cold. Mine purrs like a kitten with no hesitations once warm.You have to remember I run a manual choke and like to run with it off as much as possible .And thats on a tired old engine with no efe tube on it.

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I may be slow,but I"m ahead of you.

Read at least the document Olafla gave a link for. There are many important differences between the 318 and 225 BBD beyond "something addition added" "for emissions."

_________________
Casually looking for a Clifford hyperpak intake for cheap.

I used a 318 2280, and had to alter the choke mechanism after purchasing an aftermarket electric choke. Did not adjust anything else on the carb as of yet, other than the fast and curb idle, but I only need about half the pedal to accelerate quickly, and get no black smoke out the back... It runs great when warm or cold, but must be running rich (though it doesn't foul plugs or use more fuel than the old 1920 did). No stumble, no hesitation, no bogging... Not sure I want to disturb any settings while the old slant runs as well as ever. Feathering the pedal results in decent performance and (better?) equal fuel mileage to the old 1bbl.

frank79912, you are right about differences in the idle circuit, but as Reed say, it is only one part of a bigger picture. See this post for photo of just one example of some differences in mixture screws:
mixture screw photo

Olaf

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Aspenized

The 2280 is not the BBD, which is what we are discussing.

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Casually looking for a Clifford hyperpak intake for cheap.

I was curious about both the BBD and the Holley 2280 actually. But yes, all the info in here has been about the BBD.

So I'm getting somewhat conflicting info. The super six conversion page suggests that the only thing that needs to be modified on a 318 BBD is the choke linkage, but the page excerpt describing all the differences seems to suggest that the six will run like absolute garbage with a 318 carb.
Which is it?

318 BBDs can be made to run acceptably on a slant six. However, optimal results will be had if you use the right carburetor for the application. I believe the differences make it worthwhile to track down a slant six specific carburetor. Or, just buy one of the NOS slant six Holley 2280 carbs off of eBay for $130.

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Casually looking for a Clifford hyperpak intake for cheap.

I have ran 318 BBDs and 2280 Holleys. Never ran a slant BBD so far. If you can tune one (I'm no expert) you can do good. I have got up to 22mpg with points, 3:23's, manual 3 speed, at 82mph on my 198 in the Duster. I have done lots of highway miles with it. I also ran a Stromberg off a 318 and got the same mileage.

I got 16-17 at 65 with the A/C on.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

All I can tell you is if you use a complete carb - take a little time playing with the metering rod height and the step up travel-it runs quite well and does not have the lean miss at a idle.

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I may be slow,but I"m ahead of you.