1967 inline-6 Ford Mustang single barrel carb to double barrel carb

TwinTurboV8

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Sep 20, 2020
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Swansea, Massachusetts
Hey! I’m new to this forum and new to owning a classic car. Me and my father own a base model 1967 Ford Mustang with the 200ci inline-6. It has low miles (close to 20k by now) and we want to help the engine with its hesitation. It has slow acceleration, so we want to wake it up a little bit so we can get up to speed faster. We’re considering switching from the single barrel carb to a double barrel as I’ve read and heard that it helps the car run smoother and boosts power when tuned correctly. I’ve looked online for the pros and cons of upgrading, but can’t get a direct answer. I hope you guys can help me out here! I’ll attach a picture of my car here.
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rbohm

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Apr 12, 2002
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ok a few things here since i have done this swap, and am considering doing it with another car.

you have two options, actually a few depending on what diretion you want to go. you can

use a one barrel to two barrel adapter, there are a number of them out there. this has the advantage of simplicity and ease of conversion. i did this with my 66 falcon 170 a number of years ago. easy conversion, i used an autolite 2100 carb from something like an early 70s mustang with the 302. i think i used an adapter from trans adapt to bolt the carb on. i had to do a little clearancing of the adapter so the carb linkage would operate properly, easy enough to do and it was minor. i had my adapter set up so that the float bowl faced forward. i used a V8 bellcrank and a long rod to work the accelerator on the carb.

two issues with this set up;

1: hood clearance. i had to use a small 9" air cleaner, and even then i had something like 3/8" hood clearance at best. so be aware of that. the adapter was thick enough so that if i needed to mill about 1/4" off teh adapter overall i could.

2: in order to get the idle set properly i ended up closing off one mixture screw to get a smooth idle without an excessively rich mixture. it did not affect the operation though, but be aware of that.

at the same time i did that swap, i also switched to electronic ignition as well. now since yours is a 67 i believe you have the dual advance distributor, which means no spark control valve to deal with, so you dont need to do this step, but i recommend it anyway. i used a duraspark distributor from something like a granada or fairmont with the 200. i hooked that to a chrysler "orange" ignition box, easy to do you can find the wiring diagram here;

www.gofastforless.com

i also used an MSD blaster lll ignition coil, though when i do this conversion again i will likely use the later model ford E coil, like this one;


or one of the aftermarket coils of that nature.

now to the options you have when doing this conversion;

1: using an adapter. you have a couple of options, the holley/autolite bolt pattern or the weber bolt pattern, depending on which carb you decide to use. at the time i used the autolite carb because it was cheap, i would rather have used the 38/38 weber carb instead.

2: you can direct mount the carb to the head using the proper adapter, but that means pulling the head, or sourcing another head to do the necessary machine work. this is the preferred method though as you get better hood clearance than with the 2 to 1 adapter.

3: you can direct mount multiple carbs. this is what i am planning for my 64 falcon. i intend to use two 32/36 weber carbs as they are progressive carbs so it would be like running a four barrel carb. the primaries are smaller for better idle and low speed response, and larger secondaries for good power. it also makes the linkage much easier to deal with as i can use the stock accelerator rod, to operate both carbs, though i would still have to modify the linkage a bit.

you can find adapters here;

www.vintageinlines.com

as well as carbs, and other small six performance parts. he also has links to the old classicinlines tech section which is packed with good information on modifying the small six. and dont forget to check us out at www.fordsix.com in the forums and tech sections there. lots of guys willing to give you any information and help you may need.

let me know if you have any questions.