2 barrel to 4 barrel

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I've got it coming in the mail already. I'm an Amazon Prime member so it was only $20.00

 
dont put over 600 edelbrock carb on it. but its decent up to there. i got 21 mpg with that set up. and ran great. i had to check the milage three time before i could believe it. got a 750 on it now with 4bbl intake

 
These were obviously intended for the dailey driver to conserve gas yet save swapping everything. Actually between the 500 Holley and the 4 barrel with the right jets it wasn't half bad.

 
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I bought one of those fr my '71 fastback in 1992. It worked OK. Nothing like a 4bbl intake with the same carb.

 
So are you saying that you can get better MPG with one of these and a 4barrel carb? I was always under the impression that the 2 barrel gave better MPG than the 4s. The original owner of my other car but a 4 barrel carb and intake in the engine and it got a little worse MPG than the car was supposed to have. He did nto do a very good job as most of the bolts were loose and there werre no hose clamps on the fuwl lines.

dont put over 600 edelbrock carb on it. but its decent up to there. i got 21 mpg with that set up. and ran great. i had to check the milage three time before i could believe it. got a 750 on it now with 4bbl intake
 
So are you saying that you can get better MPG with one of these and a 4barrel carb? I was always under the impression that the 2 barrel gave better MPG than the 4s. The original owner of my other car but a 4 barrel carb and intake in the engine and it got a little worse MPG than the car was supposed to have. He did nto do a very good job as most of the bolts were loose and there werre no hose clamps on the fuwl lines.

dont put over 600 edelbrock carb on it. but its decent up to there. i got 21 mpg with that set up. and ran great. i had to check the milage three time before i could believe it. got a 750 on it now with 4bbl intake

The primary throttle blades are on some carbs much smaller than the throttle blades on the 2v carbs (Edebrock+Carter 500-625cfm). This would help the mileage and efficiency provided you stay out of the power enrichment and secondary’s as well.

This is especially true if the 2v unit leaks or does not work well .

 
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Believe it or not, but I got 22 mpg with two 500 cfm four barrel carbs sitting on a 289 backed up by a BW T10 four speed trans and 3.35 gears. This was highway driving and my foot out of it, if I smashed it down then it went to 6 mpg or worse,lol. It was all in the linkage, I had a progressive setup that only ran on 2 barrels until you opened the secondaries up and the other carb. I have also had six cylinder engines with one barrel carbs only get 10 mpg on a good day, down hill with a strong wind pushing. I also had a F250 that had a 460 that got 16 mpg loaded or unloaded, it didn't matter.

 
If you are worried about mileage you bought the wrong car. These are usually just expensive toys and not every day drivers. That being said I get about 10 with mine and was extremely happy with that number. I actually thanked a Prius driver the other day for saving enough gas for me to drive my car, dont think they were real happy with my smart a.. remark.

 
I do drive my car a fair bit so gas milegae is of some concern. My Mustang gets the bet gas mileage of the 3 vehicles that I own.

I have a 351c with a 2 barrell. Was an Advance Auto replacement for the original one- looked slightly different but it works. When I bought the car it would get about 20 MPG highway on with regular gas. Unleaded gas ruined the original engine. The replacement always got a bit worse gas milage even though it was the same kind, and that went down a bit more when leaded gas became unavilable. I also changed the points to a petronix, that may or may not have helped the MPG but definitely made changing the plugs less frequent.

Last year I changed the 3 speed to a 5 speed T5 overdrive and the highway MPG went up to 23-24. I hope that getting the carb tweaked by a prfesional I could get this up a little. I beleive it is running a bit rich but I have gotten it to run as well as a am able under my skill set. I beleive the car has 2.75 rear end whihc I have leanred is good for MPG but not good for jack rabbit starts.

Always trying to find a way to get a bit more MPG if anyone has any. Looked at getting fuel injectors but that was too expensive and was also a task I would have to hire someone to do for more expense since it is beyond my skill level.

 
Depending on how and where you drive, lower gears could actually give you better MPG. Fuel injection would work. If you want to stay with the carb, maybe a 600 CFM 4bbl. If I remember, the primaries on a Holley 600 are smaller than those of a 2bbl. And just keep your foot out of it (yeah right).

 
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