Best 4bbl

[nodemon]

I have a stock 73 318 ( has one 318 head and one 67, 273 head ).. I just bought a LD4B intake and was wanting to know what the best, reasonably priced, carb I should go with. Also looking for recommended cfm..
TIA

 

[12many]

As you may know, the best carb is one that has been tuned/dialed in after it’s installed. No carb is setup ideally out of the box, you might get close or even luck out and actually be pretty spot on just bolting it on and simply adjusting the idle and mixture screws. The composite body 625 Street Demons are nice carbs that are pretty easy to work on. Mandatory that you get the tuning kit for it as well. After some tuning I think you’d be pretty happy. There are others but that’s what I’d go with as I’ve tuned both the 625 and 750 versions and they work good

 

[Projectile Dart]

The GENERAL rule of thumb (with many arguments) is that for a street cruiser you go with an Edelbrock and for high performance and maximum tune-ability you go with a Holley. That being said, both can be tuned to work really well in either direction.
I am currently running a hand-me-down Holley on my street cruiser 360 Dart and it does fine.

 

[318willrun]

I've ran everything from 600 edelbrocks, 670 Holleys, 750 Holleys, 770 Holleys, and dual quads on 318's. I have a 670 on my stock 318 in my '80 truck, runs perfect. I had a 750 (3310) Holley on the stock 318 in a '85 Ramcharger, ran perfect. I have dual quad (2x 600 eddies) on my 318 Duster with summit cam, runs great. So what's the best ?? How well can you tune.......
I'd advise a 750 3310 Holley, or the same in Brawler, because it will work great and if you upgrade the 318 or go 360, or 383, it will still work great. LOL

 

[Darter6]

Just my thought. Maybe locate a matching set of heads.

 

[Projectile Dart]

@318willrun makes a good point, my holley is a 750 and came off my dads 1970 'cuda 383 that he daily drove from '74-'93 the carb was rebuilt around 1997-98 and just sat until I started using it a couple years ago. I had to jet it down a bit to work on my 360 and be happy but it runs great now, its a pretty versatile carb/size and can hop around to multiple projects if you have more

 

[nodemon]

Just my thought. Maybe locate a matching set of heads.

Agree..!

 

[nodemon]

I've ran everything from 600 edelbrocks, 670 Holleys, 750 Holleys, 770 Holleys, and dual quads on 318's. I have a 670 on my stock 318 in my '80 truck, runs perfect. I had a 750 (3310) Holley on the stock 318 in a '85 Ramcharger, ran perfect. I have dual quad (2x 600 eddies) on my 318 Duster with summit cam, runs great. So what's the best ?? How well can you tune.......
I'd advise a 750 3310 Holley, or the same in Brawler, because it will work great and if you upgrade the 318 or go 360, or 383, it will still work great. LOL

Never tuned a carb in my life... That I can remember, anyway. Been out of the game for 30 plus years
Are you just talking turning the mixture screws till it's right..?
I do remember having a 750 on my stock 72 318 Demon back in like 1985... If I remember right, it ran GREAT and launched when the secondaries kicked in..but after a while it didn't run right..

 

[318willrun]

Never tuned a carb in my life... That I can remember, anyway. Been out of the game for 30 plus years
Are you just talking turning the mixture screws till it's right..?
I do remember having a 750 on my stock 72 318 Demon back in like 1985... If I remember right, it ran GREAT and launched when the secondaries kicked in..but after a while it didn't run right..

well, besides the idle mixture screws..... there is... just to name a few....

• accelerator pump... If holley, were talking adjusting bolt, cam, nozzle...
• jetting..
• power valve...

Many times a carb can run "good" out of the box. No carb was set up from the factory for your specific car except the carb it came with from the factory.

 

[mvh]

Just my thought. Maybe locate a matching set of heads.

That 67 head has the same ports, and obviously it bolts up, but the combustion chamber design is completely different (small closed chambers). I wouldn't spend a nickel on a carb upgrade when I'm running a different compression ratio on each bank of cylinders. How the heck are you going to tune that? I would also suggest that a 750 is a little more carb than you need on a small port, small displacement V8. The factory solution was a 450cfm Carter AFB, and even that motor had higher compression and a more radical cam than you have. Sure, you could make it work, but at least fix the heads first.

 

[nodemon]

That 67 head has the same ports, and obviously it bolts up, but the combustion chamber design is completely different (small closed chambers). I wouldn't spend a nickel on a carb upgrade when I'm running a different compression ratio on each bank of cylinders. How the heck are you going to tune that? I would also suggest that a 750 is a little more carb than you need on a small port, small displacement V8. The factory solution was a 450cfm Carter AFB, and even that motor had higher compression and a more radical cam than you have. Sure, you could make it work, but at least fix the heads first.

I'll be making finding matching heads a priority.

 

[Professor Fate]

Best carb? Whatever I already own, sitting on the shelf. Holley/Eddy... 600/750, doesn't matter. Within reason, on the street, a 600 will run well on anything from a 273 to a 360, a 750 will get you up to a 440... and everything in between. Holley or Carter/Edelbrock, everyone can make a case for their favorite; but that's all they are is a favorite- they both can work equally well as street carbs. As said, it's all in the tuning. If you put a gun to my head and made me pick one for you, I'd say an Eddy 650 AVS2. Will work well on a stockish or warmed up 318, and is still good for a 360 build if you decide to go that direction sometime in the future. Personal favorite would be an old Carter 625 Comp. Series AFB, but I'm kinda old school at heart...
And yes, get matched heads. I'd actually lean towards getting another early one- as stated, the combustion chambers are smaller and you can use all the squeeze you can get.

 

[rumblefish360]

Best carb is like best boobs on a chick, so many flavors!

Top 4 carbs in no particular order or favorites.
All will perform great!

Edelbrock AFB or AVS II @ 600/650
Holley 1850 @ 600 cfm
Street Demon @ 625 cfm (sold by Holley)
Summit racing’s inexpensive M2008
(Seriously!, a very good carb! Uses parts from Holley)
Summit Racing Carburetors Parts & Accessories | Summit Racing

 

[TF360]

Edelbrock AVS-2 650! Research it.

 

[dano]

What are the two casting numbers for your heads now?

Id suggest a 500cfm to 625cfm AVS2, maybe a sub 600cfm Brawler or Quick Fuel.

For a cam, we'll need the static compression ratio, Gear ratio, converter stall speed or if your willing to change it, and if you willing to change valve springs.

If you interested in changing the heads I would wait until Speed Masters Black Friday and pick up a pair of heads cheap and have them gone though. I think last year you could get a set for $700 (can some one confirm that?) Then do heads and cam and intake at the same time.

 

[niceolddart]

No mention of a Thermoquad? The factory used them on mid to late 80s 318s I'm pretty sure. I've had a couple that worked awesome when the were tuned in. Mopar Action magazine had an article on them, within the past couple of months, telling you step by step how to set them up. They are a great carb & not too expensive.

 

[12many]

More carbs have been labeled garbage etc when it’s purely due to inept tuning skills vs. than simply just being garbage. Any carb if sized correctly and tuned will work fine.

 

[nodemon]

What are the two casting numbers for your heads now?

Id suggest a 500cfm to 625cfm AVS2, maybe a sub 600cfm Brawler or Quick Fuel.

For a cam, we'll need the static compression ratio, Gear ratio, converter stall speed or if your willing to change it, and if you willing to change valve springs.

If you interested in changing the heads I would wait until Speed Masters Black Friday and pick up a pair of heads cheap and have them gone though. I think last year you could get a set for $700 (can some one confirm that?) Then do heads and cam and intake at the same time.

One head # 2658920
The other # 2853675

 

[toolmanmike]

One head # 2658920
The other # 2853675

Damn, my books are home.

 

[nodemon]

Damn, my books are home.

?

 

[Professor Fate]

No mention of a Thermoquad? The factory used them on mid to late 80s 318s I'm pretty sure. I've had a couple that worked awesome when the were tuned in. Mopar Action magazine had an article on them, within the past couple of months, telling you step by step how to set them up. They are a great carb & not too expensive.

Agree, TQs are great, but since the OP said he had already purchased an LD4B manifold to use, I limited my comments to square bore carbs.

 

[j par]

As you may know, the best carb is one that has been tuned/dialed in after it’s installed. No carb is setup ideally out of the box, you might get close or even luck out and actually be pretty spot on just bolting it on and simply adjusting the idle and mixture screws. The composite body 625 Street Demons are nice carbs that are pretty easy to work on. Mandatory that you get the tuning kit for it as well. After some tuning I think you’d be pretty happy. There are others but that’s what I’d go with as I’ve tuned both the 625 and 750 versions and they work good

While I'm a known fan of the Holly Street demon I would say all carbs have to be checked.. tomorrow I'm reinstalling a 750 on a 65 Pontiac 400 and the float bowls that are supposed to be set at one inch one was set at an inch and a half and one was set at a quarter from the factory.. way off... And as far as buying one of those 80 or $90 tune-up kits not a fan either.. first off they give you yet another set of metering rods and jets that are already in the carburetor. And also you're likely going to go one way with it like leaner or richer so just bring a set or two of jets heading in the direction that you need for your particular setup would be much cheaper than an entire tune-up kit with again not only the Jets that you have and metering rods you have with the ones going the opposite way of the way you want to go... I would also recommend a $4.95 Edelbrock Summit brand spring kit as opposed to the demon Springs which are colossally expensive or even the Edelbrock Springs which are way over twice as much as the summit knockoff step up Springs....

 

[Bewy]

If you have no carb tuning experience, I would use an Edel carb. I am presuming they still come with the excellent tuning manual that is a great help. The 650 AVS2 with annular boosters would be a good choice.

 

[George Jets]

One head # 2658920
The other # 2853675

Here are specs on the 2 heads, the other # should probably be: 2843675

Edelbrock 1406 Electric Choke 600 cfm carbs work good on the 318s

Can always run the Mr Gasket 2 to 4 bbl 20.00 dollar adapter on your 2 bbl intake for now without having to swap the intake if it's up and running. Have used these with success on multiple 318s with the 1406 carbs.

 

[12many]

While I'm a known fan of the Holly Street demon I would say all carbs have to be checked.. tomorrow I'm reinstalling a 750 on a 65 Pontiac 400 and the float bowls that are supposed to be set at one inch one was set at an inch and a half and one was set at a quarter from the factory.. way off... And as far as buying one of those 80 or $90 tune-up kits not a fan either.. first off they give you yet another set of metering rods and jets that are already in the carburetor. And also you're likely going to go one way with it like leaner or richer so just bring a set or two of jets heading in the direction that you need for your particular setup would be much cheaper than an entire tune-up kit with again not only the Jets that you have and metering rods you have with the ones going the opposite way of the way you want to go... I would also recommend a $4.95 Edelbrock Summit brand spring kit as opposed to the demon Springs which are colossally expensive or even the Edelbrock Springs which are way over twice as much as the summit knockoff step up Springs....

Well I don’t know what to say when it comes to the cost of a carb kit that comes with the correct primary and secondary jets, the multitude of metering rods, and all the springs. If a guy wants to spend time and money ordering individual pieces have at it. The 750 kit DOES NOT give you duplicate rods. You get a set of richer and a set of leaner, sane with the primary jets. Pretty sure the 625 kit doesn’t come with a duplicate set of rods either IIRC, just 3 sets leaner and 3 sets richer, along with more primary jets than the 750 kit. First pic is the 750 kit, second the 625:

Best of luck on those Edelbrock springs working, they’re not the same dimensions as those used in the Street Demon. Thought I could use the Edelbrock #7 springs but no go.
The colors and strengths of both are not the same. All I can say is when it came to properly dialing in the light throttle, light acceleration, heavier throttle and WOT I was able to really zero in on each circuit using the kit as I drove and tested. I had a chart I made up of all the rich to lean combos of rods and jets. Knew exactly the combos I needed to fine tune.
The carb is one of the cheapest in cost as it is, and adding in the kit combined is still cheap, gives you all you’ll ever need, and if/when you ever sell the carb the kit goes with it for the next guy that obviously won’t have the same engine.
Buy the carb and kit and be done or buy only what you need, modify something else to fit. Not me. Gimme the kit with the carb.