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Discussion Starter #1
Hey community, probably not a new question but lookIng for some guidance on on junking my 2bbl feedback carb for a new manifold and 4 bbl carb setup. Any thoughts or issues that may arise except for emissions and visual inspections? I feel like everyone does this. Choke, vacuum advance issues. Appreciate your feedback and direction.
 

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95 Bronco, 351W, E4OD, 4.56 gears, 35x12.50x15 Patagonia MTs. 94 Bronco 5.0/E4OD/1356/3.50 gears.
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357 Posts
I ran a quadrajet on an edelbrock egr free manifold on my 78/351M. Loved it. It ran way better than stock, especially at weird angles. Gas mileage also doubled from 7 to 14, but that was due to the cam I installed. I don't think it would harm anything to go with a better designed carb, but if you have smog inspections I wouldn't touch it.
 

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82 XLT Lariat 351w, Edelbrock 1406 4bbl ,C6 auto, auto locking hubs ,33x10.5x15
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2,548 Posts
I have emissions inspection (is that different from smog?) And upgraded to the Edelbrock 4bbl #1406 and now that she's dialed in right, she runs like a top 👍
 

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Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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12,676 Posts
I thought only the 300 was saddled with that horrible feedback crap. Not sure mine (85 300) was ever inspected in colorado, but its running a 4bbl and had a points style distributor.
 

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Discussion Starter #5
Thanks for the reply guys. Not sure how many years the feedback system was in play but I have power to the module, no power coming out to carb. I just want to put a new manifold and thinking of the edelbrock carb. I think it’s an easy install, but want to be sure there are no additional issues to deal with. I’m not worried about the emissions/smog. Just need my bronco running again.
 

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Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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12,676 Posts
Thanks for the reply guys. Not sure how many years the feedback system was in play but I have power to the module, no power coming out to carb. I just want to put a new manifold and thinking of the edelbrock carb. I think it’s an easy install, but want to be sure there are no additional issues to deal with. I’m not worried about the emissions/smog. Just need my bronco running again.
Ah yeah, thats how the feedback system dies.

So what a you need is to get a 4bbl intake manifold and carb. Then you will have to swap out the ignition because that is part of the feedback system. Easiest way to do this is buy a duraspark II distributor and conversion harness. This can be found on mid 70s-83 fords. This is a very common conversion to do.

Other methods are a points and condenser distributor and wiring, with or without a digital pickup. Or going the HEI distributor route, which requires a bit of wiring too.
 

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Discussion Starter #7
Thanks for the reply, is there a discussion or link to the Duraspark II conversion? Can I purchase the harness, or is this simple splice in? Sounds like the better way to go then points.
 

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Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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12,676 Posts
Thanks for the reply, is there a discussion or link to the Duraspark II conversion? Can I purchase the harness, or is this simple splice in? Sounds like the better way to go then points.
My 85 bronco came to me with a 300-6 with the feedback system removed and a 4bbl intake and carb installed. They installed a points distributor, with a pertronix ignitor installed in place of the points. It ran well.

I dont have a specific thread or write up on the duraspark II swap. But its very common, and has been documented on the internet a lot.

Essentially you buy a duraspark II distributor for something with a 351w. Then yes, you can buy the conversion harness. Its all a pretty economical modification, and with a 4bbl carb, you'll pick up some power.
 

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1987 Bronco 351W, C6
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1,212 Posts
Like above, Eddy 1406 or one of the off-road ones if you want, no more than 600cfm. Get a good dual-plane like Eddy Performer or Weiand Stealth. Use the same power supply for the electric choke.
 
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