Carb CFM help

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73duster47

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Hey everyone,
I'm trying to figure out which carb to use on my engine, this is one of the last things I need to fire it up, and am kinda stuck.
The engine is a 360, bored 0.030" over..giving a final displacement of 365CI. Cam is a Lunati Voodoo #60403 (advertised duration of 268/276, lift of .494/.513, duration at 0.050" lift of 226 int./234 exh., RPM range of 1800-6200) Using Edlebrock RPM Air Gap intake. J heads with 2.02" intake valves. Torque converter has a stall of 2800, and rear end gear is 3.23 sure grip. This combination will be in a '73 Duster, that will be used as a daily driver but will see some drag race duty for fun as well as some autocross duty. I have a relatively heavy right foot and want to be able to break the rear end loose whenever I feel like it.
I'm very familiar with Holley carbs, so I'll stick with that brand. Never had success with any other brand, never had problems with holley in working with family and friends on their cars, just havn't had to choose a carb yet. Plus I have a shelf in the garage that is full of Holleys my dad has collected over the years, and hopefully I can use one of them.
I've done a few calculators, and used Holley's carb selector program on their website, and they recommend either a 650CFM, 670CFM, or 700CFM carb. Of course vacuum secondaries and electric choke since its an automatic street car.
So, anyone running a similar drivetrain combo, please let me know what carb CFM you're running. and anyone with ideas, let me know.
Thanks!
 
750 holley double pumper...for heavy footed drivers...
 
I wouldn't go with a Double Pumper being that it is a daily driven automatic with modest rear gearing.

I would probably go with something like this… (I used the carb selector program on the holley page)

http://www.holley.com/0-80783C


It spit out some 750s too. You may want to look at those also. I went on the conservative side.
 
Thermoquad! Small primaries for idle and mileage qualities.

Huge secondaries for that 'suck the hood thru the carb sound

800 cfm
Chrysler did not use them for no good reason.
 
I wouldn't run a DP neither, with that gear i'd stay with a vacuum secondary, my choice would be the 750 3310, i run this on my dart with 3.73s & a 2800 stall behind a mild 360 magnum & its damn near perfect.
 
I'm using a 650 cfm double pumper on a very heavy truck with 3.55 gears, 33x12.5 tires, a 360 punched .040 over with a Lunati 60401 cam, 10.2:1 comp ratio, 727 and a Hughes 4x4 converter that stalls around 1700 rpm at 5300' elevation. It is very responsive but hard on gas, lol.

You could easily run a 750 dp on your combo IF you tune your ignition and carb correctly. I'm running 16 degrees initial, 34 total all in by 2500 rpm. My jets are 74's front and rear and a 6.5 power valve. In the summer when it warms up I drop the fronts one size and the rear 2 sizes. Front shooter is a .032, rear is .028. Intake is a weiand action + with a 1" open spacer. It really needs a less restrictive intake.

You can always run a 650 vacuum secondary on the street and swap out to the 750 dp for the strip. You'll need more initial advance than I with that cam and I would start at 74's all around with a 4.5 power valve. I would also go with a 4150 style vs carb if that's the way you want to go so you can change jets on the secondary side. Sounds like a great build and enjoy your new ride.
 
Any carb will run good on that 360 you have. I run a similar motor in one of my cars and I use a 750 dp. My car has a bit more gear than yours but I think you will like the "instant on" power of the 750dp. The 3310 holley 750 vacuum secondary is a great carb and in a drag strip shoot out it would probably beat the dp, but on the street with a street tire it will feel soggy/undercarbed. This is due to having to wait for the secondaries to open (even with the lightest spring in it) and not having a secondary accelerator pump. A 650 dp will be very snappy and have really good throttle response, but you will give up hp pretty much across the board. If you have multiple carbs to play with then try a few. I dont think any one of them would be a wrong choice. You just have to decide which one suits you best. Good luck and enjoy.
 
read his original post...he want to be able to break the tires loose...and has heavy right foot.....
 
Demon with 360 and similar build was getting 19-20 MPG on the highway with a 750DP. Car runs really good with the DP carb.

You could run either a 750 Vac or DP. I'd run a DP if you are planning on beating on it good.

The tune up: Initial, curve, carb settings will make a world of difference in how it runs.
 
He said he wants vacuum secondaries and an electric choke..3310 it is i'd say..
 
I'd just about settled on the 3310 or the 80783 like was suggested before hand, so looks like the research over the past few weeks was close!

What would be the benefits of the double pumper over the vac. secondaries?

We may have a 3310 on the shelf in the garage, and I know we have a ton of rebuild kits. I'll check on that one when I get home. If not I was planning on heading out to the Pomona Swap Meet this sunday to try and find something. $300-$400 for a carb is a touch out of range at the moment...

Thanks very much guys!
 
I run a 3310 on my 340. Great carbs.

Do yourself a favor and get the spring kit and a rear metering block if the carb doesn't have a block.

I have a 750HP DP carb with a billet baseplate in the for sale section.
 
The 360 in my Cuda is very similar to yours and I have had 600, 670, 725 and 750 carbs on it. The 600 and 670 have great low mid rpm throttle reponse. By the But dyno there is no difference between the 670, 725 and 750 carbs. The 725 and 750 don't have anywhere near the throttle reponse in the low mid range and get about 5 mpg less than the 600 or 670. If you are following along the 670 is the best all around carb.

The 670 is a Holley Street Avenger. My second choice would be the 600 (a generic Holley vacuum secondary carb) becasue of the great throttle response and it doesn't really give up much on the top end to the bigger carbs but it is noticeable to the butt dyno. My third choice would be the model 3310 Holley 750 and the 725 Demon is last.

For a daily driven street car I wouldn't but a double pumper anything on it. Unless you are a very talented carb tuner you will give up to much low mid range driveability and gas mileage for little or no improvement in the top end.

FWIW, my car has run a best of 13.7 seconds at 102 mph in the 1/4 mile with the 600 cfm carb so the small carb is not really holding it back much. That is with a very traction limited 60' time of 2.2 seconds and an A833OD tranny.
 
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