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Bore size for center carb on a 440+6 manifold

69 GTX

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Can anyone give me the bore size for the center carb on a 440+6
Caliper measurement?
 
If no one helps you out today I will have it this evening when I get home from work.
 
I didn’t make it in this evening in enough time to get you a measurement but should be able to tomorrow.
 
No problem this is for a future project, just gathering info at this point.
 
Looking at installing a 4412 in the center of the 6 pak. 500 cfm carb instead of 350
 
Jet makes a 500 that they install bigger butterflies on the throttle shaft, from 1.69 to 1.75. And does some other mods that probably gives it some more cfm. It would bring the total for all three carbs to 1500+ CFM.
 
without measuring the intake openings they will have to be opened up. The stock
center carb butterflies barely clear the intake openings
 
My aftermarket edelbrock sixpack manifold has all carb throat holes at 1.720-1.770. Seems that the drivers side holes, primary and secondary are ~ 1.770, the passenger side at 1.720approx. The core shift and quality control on my manifold is abysmal.
Edit: i can give you the exact measurements of mine, but i suspect that there is variation fom manifold to manifold.
If you look closely at the passenger side throats, you can see the shelf left by the cutter, due to core shift.

20190304_110059.jpg
 
Last edited:
I'm sure my bores are all probably 1.77 knowing Jim's attention to detail. Thanks for the info & pictures!
 
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