Hello, I want to replace the carb.on the truck. I've chosen the Edelbrock line. But I'm not sure of the size to go with.{ I own a '55 with a 350; 3spd+ overdrive-just normal driving.} Should I install the 600cfm or is the 500cfm adequate for my application. Would I be overcarbureted with the 600cfm? Would I see better gas miliage with the smaller carb? Thank you for your opinions
[updated:LAST EDITED ON Apr-13-03 AT 10:42 PM (CST)]Hi Enrique, Your best bet will be the 600 cfm model if the cam and heads are all stock. If the cam is a mild grind then a 750 cfm will get the best results. Using the 500 won't effect your milage enough compared to how well the 350 will run with the 600cfm. DValentine
You could get a Quadrajet from Edelbrock thats what Chevrolet put on them. I think the Quadrajet is a 750 cfm . Butch
I would say that the 600 is the best all around carb for a smallblock, I would recomend a electric choke, they cost a little more but it's worth the bucks.
howziit guy! JMO, go with the smaller carb. in your situation, a 390cfm HOLLEY would work well, too. FWIW, the BBC454 in THE PINK LADY works GREAT, with the 750cfm eddy, gets 7-12mpg. with the 600cfm eddy carb, it doesn't make the same power, especially at mid-high rpm range. but it DOES get me 17mpg. on my '57 coupe, i thought bigger was better...750cfm on sbc 327, mild cam, etc, 3.36 gears, 3800 pounds. not too crispy, 12mpg. swapped in the same 600 eddy carb. better response, still needs work. don't get caught up in the "BIGGER IS BETTER" way of thinking. just...my...opinion.
Hi, Well I finaly got the Edelbrock Performer Series 600cfm carburetor 1406 with electric choke which is sitting on an Edelbrock manifold, installed on my truck.{1955-2nd,1978,350cid-3spd+od}. It runs real nice- but only after the engine has warmed up. In the mornings when I start up,the engine runs at fast idle ok.(at about 1300rpms). But when I start to drive, it right away goes off fast idle and feels sluggish and it seems like it wants to bog down. Once it even backed fired.As soon as the engine warms up everything is fine.I realize that it's normal for the motor not to run as efficient in the mornings but I wish that it was a bit smoother. I know that the choke plate is closing at start up and then opening as the engine is warming up.Any ideas? Thank you
I see that you already have a carb, but I will add my 2 cents for anyone looking to this thread for info in the future... The CFM rating on a carb is not going to have that much bearing on your gas mileage. The CFM should be considered strictly in respects to the flow capabilities of your heads. When you get to mileage, that is where the jets come in. If you want better mileage, you can jet it to run leaner (but not too lean), more power, run richer (but not too rich). The CFM just means how much volume of air can flow through the carb. You cant have too big of a carb, only too much fuel delivery. A high CFM carb is not going to force too much air into the engine, but it can dump too much fuel into the engine. A low CFM carb can restrict how much air goes into the engine, and can still dump too much fuel in if it is not jetted right. In short, make sure the CFM is adequate for the size of the engine and flow capabilities of the heads, pay no attention to what your desired gas mileage is. Then make sure that the carb is jetted to suit your performance/economy needs. ;-)
I have a 75 C10 with a 305. I put a Holley on it and the truck wanted to start but never did. Put a Edelbrock on right out of the box and it fired right up.....good carbs
Heres the math guys. 350cid divided by 2 then divide by 1728. Multiply answer by 6500 rpm..=658.27515 x 85% =558cfm Volumetric efficiencies will vary from 85 to 90% for street motrors and 110 to 120% for highly tuned normally aspirated racing motors. But you know that sometimes a bigger carb will make a motor run stronger mainly because of improvement in air flow quality not quantity.. my two cents..
Enrique I have to go with the cfm doesn,t matter. I have a 283 in my 64. Lots of work done to the heads to improve air flow. I milled around with 3/4 different carbs. I ended up with a holley 650 double pumper. primary,s jetted down to where it idle,s good. but if i need more fuel it;s also there. Average fuel is 11/12 if i stay out of it.
