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Discussion Starter #1
So i have a 1984 Ford Bronco, with a 2 BL Stock holly carb, i wanted to know if i could switch it to a edelbrock #1405 600 CFM

ANY IDEA? thanks guys
:thumbup
 

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Discussion Starter #3
is this hard to do? and would it cost alot $$$$ im a noob you see
 

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depends...any emissions required where you live? if not grab a haynes manual...read up...and go for it...pretty simple and you can change a intake and carb with simple hand tools.
 

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Discussion Starter #5
Yes there are emissions in colorado... it won't pass if i switch this?
 

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Discussion Starter #7
alright, well thanks
 

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Discussion Starter #9
do you have the EXACT same carb? of just switched from 2-4 br... and is 4br alot better?
 

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I used to run the stock 2 bbl motorcraft carb.
i switched to a 4bbl carb (edelbrock 1406) and actually had slightly better mileage, plus more power when needed.

you see, a 2 bbl may be seen like a compromise:
u have 2 medium sized barrels that feed the engine in different driving conditions, such as light throtle cruising, uphill driving, passing, etc.

so they tend to be slightly big for cruising, and too small for WOT (wide open throtle)..

4 bbl carbs usually have two small pair of barrels (called primaries) and two larger sized barrels (called secondaries).....the primaries are usually smaller than the ones from a 2 bbl carb.

When you need the power, stomp the skinny pedal, all four barrels open, increasing the fuel/air mix in to the engine, making more power..



so, as long as you dont floor it all the time, a properly tuned 4 bbl gives you better mileage than a 2 bbl (of course, this assumes that engine internals, ignition, etc are in good working order), because you have two pairs of barrels suited for different needs.

Keep in mind that this does not apply to Mechanically activated secondaries or "double pump" carbs used in racing..these really suck gas...and make a lot more power than a vacuum operated secondaries..

As for the manifold, if you originally have a 2 bbl manifold, it is better to get ahold of a 4 bbl manifold. stay away from 2bbl to 4 bbl manifolds, as these impair the gains of the flow of the 4 bbl.

for 302 owners a popular cheap swap is the carbureted 5.0 mustang intake (GT 4BBL) as some of these are made of aluminum.

emissions compliance is a different story.
altrough edelbrock sells an intake manifold with EGR provision, it may fail if that specific application did not come from the factory with 4 bbl optiion (like mine originally did, 5.0 w/ 4bbl). check your state laws
 

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quicksilver3602003 said:
do you have the EXACT same carb? of just switched from 2-4 br... and is 4br alot better?
You can't just switch from 2BBL to 4BBL, it requires a new manifold. To keep emissions happy, you'll need to do a bunch of work making sure you match the factory emission control layout. Edelbrock Performer carbs and intakes are 50 state legal replacement parts, but only if they don't disable existing emission controls. If there are any computer controlled functions on your stock carb, the new carb must also have them, and aftermarket carbs don't, so you may be sunk right off the bat.

Is 4BBL better than 2BBL? Depends on your driving style. On my rig, the 2BBL worked just fine.

Sounds to me like you better pick up a couple books and start getting an education on how this stuff works. Holley, SA Publishing, and Peterson Publishing all make outstanding books that help you understand how a carbureted system works.
 

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Discussion Starter #12
wow, thanks alot guys . seems like i still need to educate my self alot before getting a new carb
 

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I wouldn't say a lot, but from the sounds of things your are missing all of the basics. It only takes a weekend to go through a couple books, then you'll be better equipped to make some decisions.
 
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