Dual Quad Intake Help

[Cobra350]

Just acquired this Dual Quad Intake w/Carters. I'm not a mechanic or expert, just an enthusiast with a Slabside Kit and a built 289 in waiting and hoping to incorporate this as was told it was for a 289. Please advise of any and all you may know, thanks!

[Tom Wells]

DuckDuckGo turned this up using the part number: https://mustangtek.com/Intake/C6OA-9424-A.html

[eschaider]

Those salad mixing bowls look like they may be Martha Stewart items ...

[MAStuart]

You dog! I have been looking for one of those intakes and you probably tripped over it and fell on it. When you said carters carbs I though o another common cobra dual quad. Here you have the intake that can take 2 holleys inline. If you decide to sell I might be a buyer! Forgot to ask does it have the firing order with the number 9 cylinder?

[sd427]

The firing order is visible in the second photo, but hard to read. The last digit, the top part is hard to see, but the bottom looks like the bottom circle of the number 8.

[Tommy]

Cool find and impressive to see. But I have more questions than answers. . . . According to an online calculator, a 289 c.i. race engine at 8000 RPM requires less than 750 CFM of air flow. So two 400 CFM carbs would provide more than enough, and that leads to my question. Is there a performance advantage in running two smaller carbs over one larger carb? I can imagine it might help improve the air signal on a smaller engine to have all the air going thru one of the smaller carbs at lower power levels. Was that the principle behind dual carbs or did folks back then just think two was more than one?

[MAStuart]

I wonder what Carters those are? If your lucky they are the correct ones for the cobra lettered dual quad. The intake shown is not the same type that blue thunder repo's. There is more than one casting for these intakes that take Holley's. One of the casting included the firing order with cylinder 9. Some refer to them as the trans am intake. The blue thunder style is referred as the street intake. The runners are different between them. The Trans Am intake they say acts like a individual runner intake a wide open throttle. That intake could use much bigger carbs but thing might suffer for normal driving.

[LMH]

I can’t see enough of the carbs to tell but the correct numbers for originals are 3258S and 3259S. Choke is missing too unless you have it separate.
Manifold part number would be too late for Cobra time frame.
The hard parts to find are choke, fuel inlet, air cleaners and linkage.

BTW, those carbs are backwards on the manifold.
Larry

[Cobra350]

Excellent feedback, and now I too have more questions than answers! Again, forgive me for not being a mechanic and just loving this stuff...

The firing order is listed as '15426378'. Keep the infor coming, of course hoping its a better than new off the shelf piece as I dig that it's old school and period, just hope I can find someone to complete it with all the linkage and pieces.

Thanks again!

[MAStuart]

Post better pictures of the carbs. There are opinion's out there that the Edelbrock RPM airgap is the best all around small block ford intake.

[Cobra350]

Thanks, will do soon. There is no brand on the intake other than the model number pictured, can someone confirm who makes this one? As well, will look more closely soon but the numbers on the Carters are vague and look to be shorter than the ones suggested above and hard to read, will try to confirm those soon as well. Thanks again!

[MAStuart]

The manifolds were sold by ford over the counter and by speed dealers. They did not come any ford cars. They were made by one or more of fords many suppliers.