What size carb???

Posted By: mopowers

What size carb??? - 11/26/12 05:57 PM

What size Holley would you put on a fresh 340 in a Dart? I have a 750, but do you think it'd be too big. The car is just a cruiser. Car has an auto trans. Would a 600 work better?

Posted By: cjskotni

Re: What size carb??? - 11/26/12 06:50 PM

Yes a 750 is way too big for most applications. A 750 would be more suited for a 440 and some people even use them on BB strokers!

If I were you, I'd go with a 600 for stock/mild 340 or maybe a 650 IF the 340 is a pretty wild. Sounds like a 600 would be fine for your application.

Overcarbing will make the motor a slug down low...

Posted By: Cab_Burge

Re: What size carb??? - 11/26/12 11:23 PM

Quote:

What size Holley would you put on a fresh 340 in a Dart? I have a 750, but do you think it'd be too big. The car is just a cruiser. Car has an auto trans. Would a 600 work better?

I would put the 750 on and try it, you can always switch it later.

You may be pleasently suprised

Posted By: 70AARcuda

Re: What size carb??? - 11/26/12 11:25 PM

Quote:

What size Holley would you put on a fresh 340 in a Dart? I have a 750, but do you think it'd be too big. The car is just a cruiser. Car has an auto trans. Would a 600 work better?

your right foot controls how big that 750 gets...

Posted By: DaytonaTurbo

Re: What size carb??? - 11/27/12 01:15 AM

If the 750 you have is a regular holley 3310 vacuum secondary carb you should be able to tune it for the 340. However if the car is just a cruiser you might be happier with the extra throttle response and mpg of an edelbrock 600-650 cfm.

Posted By: YO7_A66

Re: What size carb??? - 11/27/12 01:23 AM

Can you tell us more about the 750 that you already have?
What converter and gears do you have?

Posted By: HYPER8oSoNic

Re: What size carb??? - 11/27/12 01:38 AM

Quote:

What size Holley would you put on a fresh 340 in a Dart? I have a 750, but do you think it'd be too big. The car is just a cruiser. Car has an auto trans. Would a 600 work better?

If you have a hotter-than-stock cam and 3k or more stall converter in the transmission, go with the 750 cfm. Otherwise, the 600 cfm would work well with the stock converter.

Posted By: CompSyn

Re: What size carb??? - 11/27/12 02:08 AM

I once ran a 3310 on a slightly warmed up 318 because that's what I had available to me at the time. The 750 Holley, for me, provided for a more trouble-free combo than the 600cfm Carter AFB it replaced. I'd say if you've got it, run it. A carb is always something that's easy enough to change later on.

Posted By: RapidRobert

Re: What size carb??? - 11/27/12 02:41 AM

Quote:

What size Holley would you put on a fresh 340 in a Dart? The car is just a cruiser. Car has an auto trans. Would a 600 work better?

I believe so & just me I'd suggest an eddy 1406 (600 elec choke) or any AFB that you can get a good deal on

Posted By: 340SHORTY

Re: What size carb??? - 11/27/12 11:33 AM

How can a 750 be to big when the 340-6 engines had over 1300 CFM? A 750 properly jetted would be fine. A 600 would have better throttle responce on the bottom end but lack on the top end where the 750 would still be working..

Posted By: mopowers

Re: What size carb??? - 11/28/12 06:52 AM

The car has a newer 600 edelbrock on it now. I've never been a big edelbrock fan. I had the fuel evap issue they tend to have

The 750 holley I have is a double pumper. Wish a had a holley 600vac sec for it. How much are those these days???

The 340 is basically stock. It's got a purple shaft hyd flat tappet with a stock convertor and 3.23 gear. Its just a cruiser.

Posted By: CompSyn

Re: What size carb??? - 11/28/12 07:44 AM

Quote:

Wish a had a holley 600vac sec for it. How much are those these days???

Here's one currently on eBay. $50.00 dollars and zero bids - http://www.ebay.com/itm/290818624360?ru=...4360%26_rdc%3D1

Posted By: quickd100

Re: What size carb??? - 11/28/12 11:51 AM

For a street cruiser I'd go with the 600-650 size carb, my choice would be the Edelbrock. FWIW, I dyno'd a 512 stroker that only used 780 cfm at the peak.Dave

Posted By: Paul_Fancsali

Re: What size carb??? - 11/28/12 09:20 PM

Used them all and will say on stick 340 use the 750 dbl pump or the 3310. Pure street 650 Dbl pump or 600 vac sec. On carter side use a AVS not the AFB and spread bore on spread bore intake I used TQ and Rochesters they all have there advantages. The Holleys were always faster one ecception was a maxed out AVS that was close to 750 dbl pumper time wise, but the AVS with no choke was real pain to start outside on cold days. Holleys don't really need a choke to start even on cold days if car is tuned correctly

Posted By: thedriver

Re: What size carb??? - 11/30/12 01:01 AM

750 is too big, for a sbc! My 340 only went faster when I went up in carb size, it probably used more gas? But it was way more fun, so I didn't care.

Posted By: Dan Halen

Re: What size carb??? - 11/30/12 02:26 AM

IIRC Chrysler used 800 CFM Thermoquads on 340s '71?-'73.

Posted By: quickd100

Re: What size carb??? - 11/30/12 11:44 AM

Quote:

IIRC Chrysler used 800 CFM Thermoquads on 340s '71?-'73.

Yes they did but they didn't use all 800 cfm.Dave

Posted By: terzmo

Re: What size carb??? - 11/30/12 01:45 PM

600 to 650 max

Posted By: RobX4406

Re: What size carb??? - 11/30/12 05:05 PM

Is the 750 comparable to a funnel and gas can?

I don't think I've ever run anything on my 340's smaller than a 750 Holley. If you can tune it, a 750 will run fine on even a stock 340.

If you have a 750, run it and see how you like it.

Posted By: mopowers

Re: What size carb??? - 11/30/12 05:32 PM

Quote:

Is the 750 comparable to a funnel and gas can?

I don't think I've ever run anything on my 340's smaller than a 750 Holley. If you can tune it, a 750 will run fine on even a stock 340.

If you have a 750, run it and see how you like it.

That's what I'm gonna do. Just wish it was a vac sec 750 and not a double pumper. Maybe i can get someone to trade me for a 650 DP.

Posted By: HYPER8oSoNic

Re: What size carb??? - 12/01/12 12:39 AM

Quote:

Quote:

Is the 750 comparable to a funnel and gas can?

I don't think I've ever run anything on my 340's smaller than a 750 Holley. If you can tune it, a 750 will run fine on even a stock 340.

If you have a 750, run it and see how you like it.

That's what I'm gonna do. Just wish it was a vac sec 750 and not a double pumper. Maybe i can get someone to trade me for a 650 DP.

750 vac sec would be the better deal for a "street cruiser". Considering the combo you have, you are on par with a "warmed-over" 340.
If you have to have a double pumper, go with a 650 cfm. You'd have great throttle response on the street, but with some gas mileage penalty (not as bad as you think though). The 750 cfm vac sec offers more airflow capacity, and adjustablilty of when the secondaries come in. Since you don't have too much in the way of a converter in the tranny (or rear gear ratio), the vac sec would be ideal for good gas mileage. Your chioce though, choose wisely!!

Posted By: RobX4406

Re: What size carb??? - 12/01/12 12:54 AM

Quote:

Quote:

Is the 750 comparable to a funnel and gas can?

I don't think I've ever run anything on my 340's smaller than a 750 Holley. If you can tune it, a 750 will run fine on even a stock 340.

If you have a 750, run it and see how you like it.

That's what I'm gonna do. Just wish it was a vac sec 750 and not a double pumper. Maybe i can get someone to trade me for a 650 DP.

I wouldn't trade.

Furl economy will be directly related to your right foot. I've tune up cars with a 2500 converter and 2.76 gears and run 750DP's on 340-360 engines... they got 19-22 mileage on the highway. All ran in the 103-108 range for MPH so they weren't slouches.

A tuned 750 DP will beat a 750 VS tuned up every time on a 340. BTDT got the shirt and the bad time slips...

Posted By: mopowers

Re: What size carb??? - 12/01/12 12:59 AM

So, do you think a 650dp would be a better choice than a 750dp? I would think it would give better throttle response on the street. This isn't a race care we're talking about. Just a street cruiser.

Rear will have 3.73s most likely.

Posted By: RobX4406

Re: What size carb??? - 12/01/12 01:06 AM

Run the 750, get the ignition tune up right and learn to tune the pump shots...

With 3.73 gears, run the 750.

I used to buy into the VS for autos til I learned the real deal.

You can cruise it with just about anything. Put a 600 VS carb on it if you really don't care.

Posted By: mopowers

Re: What size carb??? - 12/01/12 01:08 AM

Thanks buddy. I'll give what I have a shot first before I spend any money (750dp). I appreciate your help.

Posted By: RobX4406

Re: What size carb??? - 12/01/12 01:10 AM

Quote:

Thanks buddy. I'll give what I have a shot first before I spend any money (750dp). I appreciate your help.

I have a saying...

Nobody will spend your money faster than OTHER PEOPLE!

Run what you got is my suggestion.

Posted By: Dunnuck Racing

Re: What size carb??? - 12/01/12 01:55 AM

Quote:

Quote:

Thanks buddy. I'll give what I have a shot first before I spend any money (750dp). I appreciate your help.

I have a saying...

Nobody will spend your money faster than OTHER PEOPLE!

Run what you got is my suggestion.

Probably the best advice Ive seen on this site in months.

Everybody has their favorite but most any carburetor type will run well when properly set up.
I would run the 750 in a heartbeat. The primary side of it is most likely smaller than a 2 barrel that came on a million 360 engines

Posted By: terzmo

Re: What size carb??? - 12/01/12 02:03 AM

Quote:

Run the 750, get the ignition tune up right and learn to tune the pump shots...

With 3.73 gears, run the 750.

I used to buy into the VS for autos til I learned the real deal.

You can cruise it with just about anything. Put a 600 VS carb on it if you really don't care.

I ran a 750 dual feed/double pump proform and was not excited about the power and it bogged off the line...outside of that...it accellerated fine after 1st but I guess We all know better than the detroit designers that didn't run a 750 on a stock 340

Posted By: 70AARcuda

Re: What size carb??? - 12/01/12 02:08 AM

Quote:

Quote:

Run the 750, get the ignition tune up right and learn to tune the pump shots...

With 3.73 gears, run the 750.

I used to buy into the VS for autos til I learned the real deal.

You can cruise it with just about anything. Put a 600 VS carb on it if you really don't care.

I ran a 750 dual feed/double pump proform and was not excited about the power and it bogged off the line...outside of that...it accellerated fine after 1st but I guess We all know better than the detroit designers that didn't run a 750 on a stock 340

you ever check the accelerator pump arm to make sure it is adjusted right....check the squirter size...or try different pump cams?

all need to be tuned...