Carb CFM recommendations

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You might like a 204 / 214 429 / 444 or similar cam better in your driver. Keep the 14 inch tires and a 3.23 gear.
You probably didn't want to hear that but you will love boiling the tires and accelerating hard from 800 rpm up.
 
ir3333 said:
You might like a 204 / 214 429 / 444 or similar cam better in your driver. Keep the 14 inch tires and a 3.23 gear.
You probably didn't want to hear that but you will love boiling the tires and accelerating hard from 800 rpm up.
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Thanks but cam has already been installed. Too late to change now.
 
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Since you don't care about performance, any carb will do.

For what its worth, when I lived in Colorado, I started out with a 318 in my 67 Barracuda....that motor I had a Holley 650dp on it, and it was happy....Drove it from Golden to Greeley all the time. This was back when she was slow (high 16's in the 1/4).....She was a good daily driver.
 
Your taking the words written to the extreme. Stop being ridiculous. You have a bunch of people here trying to help you.
 
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Mattax said:
IMO skip LD4B and don't look back.
It would only be of use at the strip.
Study what happened when an LD4B replaced a factory intake on a stock 340.
Edelbrock LD4B
Below 3500, the gains from installing headers were practically lost.
Something to think about.
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Thanks! That is awesome information. Very helpful!!
 
TrailBeast said:
I absolutely agree with you and Jason both here.
Put something on there that is easy to deal with, set it and drive the heck out of it.
600 is plenty for a driver 318.

I got my Edlebrock 600 electric choke out of the pick and pull for 40 bucks and it's been flawless on my 5.9 Daily driver now for 3-4 years.
They are also on craigslist for 100 bucks or less all day long.
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Great advice. The main reason I chose the Eddy 600 was familiarity and ease of setup. The only reason I am going new is essentially everything under the hood is brand new. I really hate to top off a brand new engine with a used carb. Looks will matter somewhat on this car. It is not a frame off restoration, but the body is perfect with brand new paint. It has new interior and a new top. It will be taken to some car shows, even if they are just the amateur pop your hood type shows.
 
flyfish said:
Since you don't care about performance, any carb will do.

For what its worth, when I lived in Colorado, I started out with a 318 in my 67 Barracuda....that motor I had a Holley 650dp on it, and it was happy....Drove it from Golden to Greeley all the time. This was back when she was slow (high 16's in the 1/4).....She was a good daily driver.
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Just to clarify, performance is still important. But we are looking for midrange power and consistent throttle response. We just do not care about maximizing peak horsepower at WOT above 5K rpm. And I have seen from others that it is easy to kill bottom performance end with too big of a carb.
 
600 Edelbrock. One and done. But don't get the 1406. Get the 1405. The 1406 is the emissions carburetor calibrated for fuel mileage. The 1405 has an actual performance tune.
 
RustyRatRod said:
600 Edelbrock. One and done. But don't get the 1406. Get the 1405. The 1406 is the emissions carburetor calibrated for fuel mileage. The 1405 has an actual performance tune.
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The 1405 is manual choke and the 1406 is electric choke. Beyond that they are essentially the same carb. I cannot use a manual choke carb.
 
thecatsfan said:
The 1405 is manual choke and the 1406 is electric choke. Beyond that they are the same carb. I cannot use a manual choke carb.
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Wrong. The 1405 can have the choke added easily. The difference is exactly as I described. The 1406 is very lean. The 1405 is tuned for performance. There's a thread on it around here somewhere showing all the differences. The passages in the boosters are different. The boosters themselves are different. Good luck if you get the 1406. Unless the engine is truly dead stock or really close, you may have trouble. If it's really over 9:1 compression it's going to want more than the 1406 I believe.
 
Then you might as well take the carb you are most familiar with - the 600 eddy. I have one on a vehicle now and it runs good. However, keep in mind, you don't need our permission for anything on your car. If you already know what you are going to run, just bolt it and go.
 
318willrun said:
Then you might as well take the carb you are most familiar with - the 600 eddy. I have one on a vehicle now and it runs good. However, keep in mind, you don't need our permission for anything on your car. If you already know what you are going to run, just bolt it and go.
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Exactly. But he did ask for opinions. lol
 
thecatsfan said:
Recently ordered a 318 long block assembly and waiting for it to ship. Getting the rest of the parts together to complete this build to drop into a 67 Cuda. The 318 is a standard LA block with stock heads. Upgraded to 9.5 to 1 flat top pistons, a mild performance cam (.450 lift with 272 duration and 110 separation), high performance valve springs and push rods and double row timing set. Everything else is pretty much stock. With a 4 barrel and headers, this engine should be around 275 to 285 crank hp, with a cam hp range from 1500 to 5000 rpms. This is not a race car. This is a convertible being rebuilt as a sentimental family restoration and we simply are looking for a daily cruiser with moderate performance and responsive drivability. I am doing all of this as a favor to a sister who bought this car in the 70s as a teenager. She is paying for parts only.

I am putting an Edelbrock 4 barrel performer intake and planning for an Edelbrock carb. I would love an LD4B intake, but everyone wants more for a beat up used intake than a new Edelbrock. For carb, the best options I can buy from Edelbrock are the 1406 which is a classic style 600 cfm square bore, or the new AVS2, which only comes in 500 or 650 cfm. 500 seems small to me, but 650 seems like too much. The sweet spot for this engine seems to be around 550, but that is not an option Edelbrock. I like the new design with annular boosters, but do not want to undersize the carb.

I should mention that we live at 5K feet elevation.

Any recommendations from experience would be appreciated.
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I like the Holley 80457 600 vacuum secondary carb... It's just like the 1850 600 cfm, but comes with electric choke and is calibrated for a late 60's early 70's engine and is less expensive... Just make sure to adjust the accelerator pump correctly and then get the Holley vacuum secondary spring assortment and install the small yellow spring in the vacuum secondary pod...


We installed an 80457 on Eddie's 340 when we built it for his 69 Dart... He later had a shop change it to a Holley 650 and it didn't run as well, so we changed back to the 80457 600 vacuum secondary...

Here's a video of Eddie's Dart after we put the Holley 80457 back on and used @halifaxhops recurved distributors that he custom curved for us.... I had to let out of it early on the third pass as it came out too hard and I didn't want to loose it... This is just a mild cam in a 340 with Doug's headers idling at 800 RPM... We just stomped the gas from idle to break the tires loose, no need to brake torque it...

 
Original 1970 318
Ede Performer intake.
Ede 600cfm.
340 HiPo manifolds.
Electronic ignition.
Dam thing burned rubber all the way down the street !!!!

Picture 498.jpg
 
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Ahhhh.. why not. I'll join the fun as well.. 670 Holley on 318, stock exhaust manifolds, stock converter, 2.76 gears, summit cam and home ported heads (43 year old short block untouched). It's a little faster now with the 770 Holley....
 
The 600 Edelbrock is a great carb, but you might like to know that the 650AVS2 has the same primary size as the 600, but when you need it the secondaries are larger (same as the 800) but will only supply what the motor wants. And the AVS2 has annular boosters for better throttle response.

I have run all 3 but really like the 650 AVS2! Square bore pattern but really a spread bore design.
 
At 5k ft elevation, a normally aspirated engine is gonna pull in about 80% of the air at sea level. So stick with the smaller carbs.
 
midnight340 said:
The 600 Edelbrock is a great carb, but you might like to know that the 650AVS2 has the same primary size as the 600, but when you need it the secondaries are larger (same as the 800) but will only supply what the motor wants. And the AVS2 has annular boosters for better throttle response.

I have run all 3 but really like the 650 AVS2! Square bore pattern but really a spread bore design.
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I would like to try one. I have a few carbs I can sell to get a AVS2.
 
Another intake, very similar to LD4B, but with large port exit. I seriously doubt you'd know the difference by seat of the pants driving on the port mismatch. DODGE 5.2L/318 Mopar small block LA Weiand Stealth Intake Manifolds As nm9stheham stated, at the 5000 feet of elevation, the 500 CFM AVS II will be the carb you'll be the happiest with for cruising. The 570 Holley street avenger is another good candidate. The words that stand out most in your description are "cruiser with good throttle response and driveability with moderate performance" and "not a race car". Stay small and be happy, CFM ratings are overrated anyway. It's fairly well documented by people that have to make 700 hp or more with a 390 cfm Holley four barrel (along with a plate with four 11/16 inch holes mounted one inch beneath it!) that if the carb is undersized, the extra vacuum signal generated by the engine goes past the vacuum level that the carb is rated at and the carb flows more air at that point.
 
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RustyRatRod said:
Wrong. The 1405 can have the choke added easily. The difference is exactly as I described. The 1406 is very lean. The 1405 is tuned for performance. There's a thread on it around here somewhere showing all the differences. The passages in the boosters are different. The boosters themselves are different. Good luck if you get the 1406. Unless the engine is truly dead stock or really close, you may have trouble. If it's really over 9:1 compression it's going to want more than the 1406 I believe.
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Not sure that writeup is factually accurate. I called Edelbrock. 1405 and 1406 have extremely minor differences. Primary and secondary venturies are identical as well as boosters. Primary jets are 0.98 and 1.00 - a 2% difference in flow area. Secondary jets are identical. Metering rod is the same diameter but slightly shorter on the 1405, which makes the carb run leaner. So slightly leaner primary jet on 1406 and slightly leaner metering rod on 1405, which makes both carbs essentially equal out of the box. And for $5, I can change the primary jet on the 1406 to make it identical to the 1405. Or for $75, I can put an electric choke on the 1405. Don't forget at altitude, engines run rich unless jetted down. And just for information, higher compression does not flow more air. Bore and stroke do not change. It still pulls in 318 inches of air per combustion cycle. You still need a 13.8:1 air to fuel ratio - same amount of air and gas.
 
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Garrett Ellison said:
Another intake, very similar to LD4B, but with large port exit. I seriously doubt you'd know the difference by seat of the pants driving on the port mismatch. DODGE 5.2L/318 Mopar small block LA Weiand Stealth Intake Manifolds As nm9stheham stated, at the 5000 feet of elevation, the 500 CFM AVS II will be the carb you'll be the happiest with for cruising. The 570 Holley street avenger is another good candidate. The words that stand out most in your description are "cruiser with good throttle response and driveability with moderate performance" and "not a race car". Stay small and be happy, CFM ratings are overrated anyway. It's fairly well documented by people that have to make 700 hp or more with a 390 cfm Holley four barrel (along with a plate with four 11/16 inch holes mounted one inch beneath it!) that if the carb is undersized, the extra vacuum signal generated by the engine goes past the vacuum level that the carb is rated at and the carb flows more air at that point.
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Thanks. Great advice. I am going to stay small. I am starting to lean towards 500 cfm.
 
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