What size carburetor should I be using LA 360 engine?

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67DodgeDart360

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What size carburetor should I be using on my LA 360 engine? Right now I have a 670 Holley carburetor. It has a mild cam. The mechanic says the 670 carburetor is too small on my LA 360 engine. And it’s not getting enough gas in the engine. He said I need a 750 carburetor. Right now the car stalls out when I put it in gear.

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What size carburetor should I be using on my LA 360 engine? Right now I have a 670 Holley carburetor. It has a mild cam. The mechanic says the 670 carburetor is too small on my LA 360 engine. And it’s not getting enough gas in the engine. He said I need a 750 carburetor. Right now the car stalls out when I put it in gear.

View attachment 1715628933
Fire your mechanic...
 
Learn how to diagnose and work on your own car. That way, you're not at the mercy of someone who may not know what they're doing.
 
When I see a post like this the first thing I do is check and see where they live..
My first instinct is to just go over there and show them how to fix their car...
 
Does your mechanic know how to tune a carburetor? Does your mechanic have or own a timing light?..
My son is a mechanic ase-certified neither the knowledge to tune a carburetor or does he own a timing light...
Modern mechanics just plugged the car into the computer and the computer tells them what to do and how to do it..
 
It might PERFORM better in a race with a 750, but it certainly should run like a champ with that 670 and perform well at idle, going down the road, and wide open throttle. Actually, it would run like a champ with a factory 360 2bbl. I have a 670 on my 5.9 magnum and on my 318 in my '80 Dodge truck. Both work great!!! I agree with RRR, learn to work on this older stuff.
 
When I see a post like this the first thing I do is check and see where they live..
My first instinct is to just go over there and show them how to fix their car...
You and me both.

J.
 
What size carburetor should I be using on my LA 360 engine? Right now I have a 670 Holley carburetor. It has a mild cam. The mechanic says the 670 carburetor is too small on my LA 360 engine. And it’s not getting enough gas in the engine. He said I need a 750 carburetor. Right now the car stalls out when I put it in gear.

View attachment 1715628933

What jpar said. First thing I would do is to look for vacuum leaks. Easy and FREE!

Reset all the settings on the carb back to factory, check your plugs AND wires, and, aw hell with it. You have a piece of junk. Ill give you a hundred bucks for the car.
 
Unless your cam is in the lower to upper .500 lift range the 670cfm carb is plenty good.
Your carb is probably not on the idle circuit is the reason it is stalling when put into gear. Could be a vacuum leak too.
Your "mechanic" should know this.
 
I never could figure out how Holley could rate the 670 SA's at 670 cfm when they have the same venuri and throttle bore sizes as a good ol 1850, which is rated at 600 cfm.

Either way, one of those should work fine for a stock 360, though I never liked the 670SA that's sitting on my shelf. Those things are tuned way lean from the factory and take quite a bit of tuning on anything more than a stock engine.
 
Does your mechanic know how to tune a carburetor? Does your mechanic have or own a timing light?..
My son is a mechanic ase-certified neither the knowledge to tune a carburetor or does he own a timing light...
Modern mechanics just plugged the car into the computer and the computer tells them what to do and how to do it..

I was an ASE mechanic and I didn't know how to work a carburetor or timing light at the time. ASE test dosen't really cover the older stuff anymore. Its more modern and up to date with the technology being used in today's cars and trucks.

If all it took was to plug in a computer and fix it I would have never left the field. Its not that straight forward. Yes the scantool does give you trouble codes and those give you an idea on where to start looking. And yes you plug in the codes to the computer and it gives you a trouble tree but unless your up to date with training, good luck. New technology is always emerging, try interpreting a schematic for these newer cars.

Before I left the chevy house I found out that the fuel pumps have their own computer outside the tank thats separate from all the rest.
 
What size cam? Duration wise.
Did you change (upgrade) the torque converter?

If it truly the carb, then you probably don’t have enough of the primary throttle blade open.

For a street bound driver, 670 is fine. What you can, but probably shouldn’t put up top is two different things. I can have tour car running and performing excellent with a 450 - 4bbl or a 850. Everything is in the tune and settings on set up. How well these carbs for you is another story on what you like. Or the car likes.

318WR is %100 correct.
 
I was an ASE mechanic and I didn't know how to work a carburetor or timing light at the time. ASE test dosen't really cover the older stuff anymore. Its more modern and up to date with the technology being used in today's cars and trucks.

If all it took was to plug in a computer and fix it I would have never left the field. Its not that straight forward. Yes the scantool does give you trouble codes and those give you an idea on where to start looking. And yes you plug in the codes to the computer and it gives you a trouble tree but unless your up to date with training, good luck. New technology is always emerging, try interpreting a schematic for these newer cars.

Before I left the chevy house I found out that the fuel pumps have their own computer outside the tank thats separate from all the rest.
Of course alignment shocks breaks things like that have to be done manually. And all the fixes have to be done manually as well. But in the new new dealerships they're plugging these 2018 cars in and it gives what's wrong with it with the code is what the code means and what parts you have to replace and what tools are required to do it. It's much more modern the 15-20 years ago...
 
Read posts 2 and 5 over and over because that’s the straight poop.

Learn this stuff for yourself. You’ll be better off.
 
Of course alignment shocks breaks things like that have to be done manually. And all the fixes have to be done manually as well. But in the new new dealerships they're plugging these 2018 cars in and it gives what's wrong with it with the code is what the code means and what parts you have to replace and what tools are required to do it. It's much more modern the 15-20 years ago...

I doubt it, their not that advanced yet. I still swing by the old dealership to hang out with my friends. If anything they tell me its more complicated now. Yes they'll eventually be part replacers but not any time soon. I left in 2014 btw.
 
It is more complicated now. That is why I keep owning 90's Dakotas. I can diagnose and fix them myself. My son is a tech at the local Dodge dealership and the computer diagnosis stuff is what he does. Way more advanced and complicated now than in the 90's.
 
Never mind parts replacers, alot of problems are new repaired with computer updates/software.

As per the OP, can you baby it/feather the pedal and keep it running in gear at all, how's it idle in neutral. What do the plugs look like. Check your idle mixture screws ( google different ways/videos how to learn this).
 
While it's probably not the carburetor (unless the tune is exceptionally bad or it's sucking wind somewhere, like a bad intake to carb adapter gasket), I like this carburetor quite a bit for a 360.
[FOR SALE] - Thermo-Quad
 
Never mind parts replacers, alot of problems are new repaired with computer updates/software.

As per the OP, can you baby it/feather the pedal and keep it running in gear at all, how's it idle in neutral. What do the plugs look like. Check your idle mixture screws ( google different ways/videos how to learn this).

Updating software has come a long way too. I remember at times it would take hours to set up a new module. Now you can knock it out in a couple of minute's.

Its crazy how simple updates can fix a lot of customer complaints.
 
It is more complicated now. That is why I keep owning 90's Dakotas. I can diagnose and fix them myself. My son is a tech at the local Dodge dealership and the computer diagnosis stuff is what he does. Way more advanced and complicated now than in the 90's.

Hell yea brother, same here! While my buddies are racing to own the newest powerstroke or duramax. I'm on Craigslist looking for a square body suburban I can ls swap.
 
Quick and easy;
Assuming the fuel is fresh, the fuel level in the bowl is correct and stable, the secondaries are closed up tight, the PCV is correctly plumbed, and the Distributor advance springs are both in there and working;
Defeat the Vacuum advance.
Reset the Idle-Timing to 8*,
set the mixture screws to 1 turn,
and idle it up until it quits stalling when going into gear.
There's a start.
 
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