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www.lifted4christclub.com
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Discussion Starter #1
forgive me if this has been asked before, but with dial up, hard to do the search, I didn't find what i was looking for. my 2 barrel on my 351m (78 bronco) is running like crap,choke not working and idles rough. i was either going to rebuild it or buy a new one. but my question is, if i get a 4 barrel intake and carb, do i need to swap out cam too? what difference will i see in mpg? thanks guys.
 

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www.lifted4christclub.com
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Discussion Starter #2
forgot, i was going to go with a holley 600 cfm for my 4 barrell
 

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You don't need to change your cam at all with a 4 barrel carb and intake. Don't go too big - I'm sure others can comment on what size would be appropriate, but no need to go any bigger than 600cfm especially with an unmodified 351M (or 400 for that matter).

sure, mileage will suffer a bit. make sure youre engine is tuned up - ignition and fuel system all in proper working order - to get the best mpg.
 

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www.lifted4christclub.com
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Discussion Starter #4
yeah, i'm putting on a msd distributor and wires, new coil, new plugs. i guess i'll have to see what money i have, if i can swing getting a 4 barrel manifold and carb, or just rebuild my 2 barrel.
 

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machine gun preacher
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I actually got better milage when I switched to a edelbrock 4bbl on my bronc. Probably because the old 2bbl was shot, but it was nice.
 

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www.lifted4christclub.com
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Discussion Starter #6
thats what the guy that works on my bronco said, it woudl get better mpg with a new carb, but i'm still debating on doing that or just rebuilding my 2 barrell. it's mostly street driven, but i do like to take it off road, but it has enough power for me with the 2 barrel
 

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House of Windsor 4ever!
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You'll call me crazy when I tell you this, but if you go to a 4bbl with no change in your bumpstick, you should get a new Edelbrock Quadrapuke for your engine, because a spreadbore (primary bores smaller than secondary bores) will give you better mileage than a squarebore (primary and secondary
bores the same size) when you're not putting your go pedal to the floor. Just my 2 cent's worth.
 

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www.lifted4christclub.com
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Discussion Starter #8
i wouldn't buy an edelbrock carb though, i've had them before, nothing but problems with them, i like the holleys, but thanks for that, that does make sense, all in how your 4 barrel is set up
 

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Id get the four-barrel. Two barrel carbs get crappy MPG. The four-barrels get better MPG because they are progressive carbs and two-barrels are'nt. On a 650 cfm carb it is only 650 cfm when the secondarys are open.
 

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www.lifted4christclub.com
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Discussion Starter #11
i guess that settles it, i'll get a 4 barrel, makes sense to me, now i need to save up for a manifold and carb. thanks guys
 

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www.lifted4christclub.com
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Discussion Starter #12
man, after pricing the 4 barrel carbs, i really can't come up with the money for a carb and manifold, i guess i'll have to just stick with the 2 barrel for now. how much does it cost to get mine rebuilt, or is it not that much more to just buy a new/reman one?
 

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www.lifted4christclub.com
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Discussion Starter #14
yeah, but you never know what you are going to get, if i'm going to replace this carb, i want a new or reman. carb. i dont' want to get one used then have to rebuild that one. i will look at craigslist if i can't find it on here, thanks
 

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I would suggest you replace the Motorcraft 2150 with another one or rebuild the one you have.

Air out = air in. If the air fuel ratio is correct the engine doesn't care what kind of carb or FI is on top of it.

The 2150 is excellent for off camber & steep incline work.
 

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www.lifted4christclub.com
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Discussion Starter #16
yeah, i'm going to just have to do that, can't swing a 4 barrel and manifold at this time. anyone ever rebuild one themselves? how much woudl it run to have it rebuilt?
 

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You could run a two barrel Holley. They bolt on without an adapter and they make a 350 CFM and 500 CFM. They're cheaper than a new Motorcraft. Having yours rebuilt is the cheapest way to go.
 

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www.lifted4christclub.com
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Discussion Starter #18
what cfm is the stock carb? i think i'll take a stab at rebuilding mine.
 

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I just got a brand new never used Edelbrock 1403 on Friday, I paid $125 for it, tis normally in the $300 range - found it on Craigslist of course, I'd normally go for a Holley as I had a spreadbore double-pumper on my Chevy and I know them fairly well, but couldn't find one in decent condition with a decent price. I really like the spreadbore design tho, small primaries to keep the air speed high, big secondaries for when you need the big airflow - I actually had an intake that uses that idea too, the ports are split in 1:20 ratio, the primaries feed the small parts, teh secondaries feed the big ones, the combination was so good I was getting consistent 19-20mpg freeway, (that with the 33" swamper tires and a TH350 tranny), yet truck would light 'em up thought every single gear and try to go sideways on me every time I hit 3/4 throttle... Gotta find one one of those intakes for the 429 now :D
 

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www.lifted4christclub.com
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Discussion Starter #20
thanks for that info, i think i'll stick with the 2 barrel for now, just rebuild it, then later on when i move back to michigan i can maybe do the 4 barrel
 
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