Holley Street Avenger 670cfm to big for 318cui?

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Hi,

i have bought some new parts for my stock 1969 Plymouth Barracuda, 318 small block with 4 speed manual.

I read the following article:
https://www.streetmusclemag.com/news/common-upgrades-for-an-la318-in-a-1971-dodge-dart-swinger/

Therefore, I decided to also buy the 670cfm Holley Street Avenger.

After searching some more information I am now unsure about the decision.

Is this carburetor too big for my 318?

I have bought the carburetor at Summit. Should I send it back and get a smaller one?
Which one would you recommend for my setup?


This is the list of parts what I have bought:

Carburetor:
Holley 0-81670 - Holley Street Avenger Carburetor
(670 cfm, Square Bore, 4-Barrel, Vacuum, Manual Choke, Dual Inlet, Silver, Each)

Intake Manifold:
Weiand Intake Manifold 8022WND Stealth Aluminum

Valve Covers:
Mopar Performance P5007613AB Valve Covers

Air Cleaner:
Holley 120-153 - Holley Vintage Series Air Cleaner

Ignigtion:
MSD Ignition 6425 - MSD Digital 6AL Ignition Controller
MSD Ignition 8203 - MSD Blaster 2 Ignition Coil
MSD Ignition 85551 - MSD Pro-Billet Distributor


Thank You
Greetings from Germany
 
No, it should be fine. My 318 really liked the 570 Holley but it will run fine with the 670. I now run the 670 on a 5.9 which runs well but tried an 870 and it ran just as fast but was less responsive on the street and was fouling plugs.
 
I've run a 750 cfm TQ on a 273, As long as the fuel mixture is good, I would not worry about it. I see you have a 4 speed that should help.
 
Keep it and run it. Once you spend a little time tuning it so it doesn’t run rich or lean, it’ll be just fine.
 
An interesting note about those 670 SA's - They have the same venturi and throttle bore diameters as a regular old 3310, which Holley rates at 750 cfm. Not sure how they come up with these ratings.
 
Thank you guys for your feedback!
I'll keep the 670cfm.


Now I have another question wich may is not worth an extra thread.
I have bought a "Weiand Intake Manifold 8022WND Stealth Aluminum".
Weiand 8022WND Weiand Stealth™ Intake - Chrysler Small Block V8

In the desciripion it is stated to fit for 318 - late style.
What does that mean? Will it fit my 1969? Or do I need another intake manifold?
 
Carb will work just fine. Intake will work, I think they mean LA style.
 
The area you may have difficulty with is the carb's circuit calibration.
If so, as long as you are willing to spend the time and energy, it can be recalibrated with some home shop work.

In my opinion potentially the MSD 6AL and distributor are going to be the bigger headaches.
Some of that is luck of the draw (quality)
The rest depends on what has been done to the engine.

If its a stock engine the issues will be:
The carb is likely to be rich at idle and take some effort to tune for good low speed.
Its going to be rich because it will have strong manifold vacuum. (Low MAP) with a stock cam etc.

The distributor issue will mostly be the advance curve. Chrysler engines like the two stage advance and the MSD distributors advances are really not good for creating an advance curve shaped like that.

my
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The area you may have difficulty with is the carb's circuit calibration.
If so, as long as you are willing to spend the time and energy, it can be recalibrated with some home shop work.

In my opinion potentially the MSD 6AL and distributor are going to be the bigger headaches.
Some of that is luck of the draw (quality)
The rest depends on what has been done to the engine.

If its a stock engine the issues will be:
The carb is likely to be rich at idle and take some effort to tune for good low speed.
Its going to be rich because it will have strong manifold vacuum. (Low MAP) with a stock cam etc.

The distributor issue will mostly be the advance curve. Chrysler engines like the two stage advance and the MSD distributors advances are really not good for creating an advance curve shaped like that.

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Just curious - if not the 6AL, what ignition do you recommend?
 
Just curious - if not the 6AL, what ignition do you recommend?
Assuming its a stock '69 2 bbl 318 ?
Going to a four barrel, probably a Pertronix in factory single point distributor set up with a curve similar to '67 273 4 bbl.
But if the 6AL works, I'd use that with a single point distributor set up with a curve similar to '67 273 4 bbl.

I think the difference between the kettering and the multispark ignition in terms of producing a good burn are going to be too small to notice here. So then its just a matter of reliability. And it seems that nothing aftermarket has been really bulletproof in recent years. :(
 
Thank you guys for your feedback!
I'll keep the 670cfm.


Now I have another question wich may is not worth an extra thread.
I have bought a "Weiand Intake Manifold 8022WND Stealth Aluminum".
Weiand 8022WND Weiand Stealth™ Intake - Chrysler Small Block V8

In the desciripion it is stated to fit for 318 - late style.
What does that mean? Will it fit my 1969? Or do I need another intake manifold?
The "early style" 318 was the poly. Their choice of words is poor. They should have said that it fits all "LA" engines. They mentioned the 340 & 360, which were both "LA". LA simply means "lightweight A".
 
I think you will be fine, the street avengers tend to run alot leaner than other similar sized carbs.
 
I will disagree with the other opinions & suggest you swap the Holley for an Edel AVS2 carb.
My reasons?
- main reason is that although both carbs have similar cfm ratings, the Edel has smaller primaries [ secondaries are larger to give the total of 650 cfm]. Smaller primaries, all else being equal, give better response/feel. With the H carb, all four bores are the same size. Plus, the Edel has annular boosters in the primaries. The combination of the smaller pri bores AND the ann boosters will give better throttle response on the primaries, where most driving is done. Fuel economy should also be better.
- the engine is stock. So a carb that 'livens up' an otherwise stock, low power engine will make you feel like the expense of a new carb was worth it.........
 
I will disagree with the other opinions & suggest you swap the Holley for an Edel AVS2 carb.
My reasons?
- main reason is that although both carbs have similar cfm ratings, the Edel has smaller primaries [ secondaries are larger to give the total of 650 cfm]. Smaller primaries, all else being equal, give better response/feel. With the H carb, all four bores are the same size. Plus, the Edel has annular boosters in the primaries. The combination of the smaller pri bores AND the ann boosters will give better throttle response on the primaries, where most driving is done. Fuel economy should also be better.
- the engine is stock. So a carb that 'livens up' an otherwise stock, low power engine will make you feel like the expense of a new carb was worth it.........
I just replaced my Street Avenger 670 with an AVS2 650. Yes, the low speed throttle response is a little better, but not significant. Fuel economy should be better because unlike the Holley, the AVS2 only opens the secondaries at near WOT. Either one should be fine. The AVS2 comes with a 3/8" fuel inlet nipple, so I had to take the nipple off of my original AVS and put it onto the new carb because my stock fuel line is 5/16". Basic tuning of the new carb was simple. Bought the jet kit but don't need it for my basically stock engine.
 
Keep the 670 and tune it. I run that on my 68 318 with the stock cam and headers. Ran real good after just tuning to what the motor wanted
 
Personally, I prefer 1200 cfms on my 318...... hooked direct, 1 to 1 :)

:poke:
:poke:
 
I have a 300ish HP 328" (.060" over 318) in my pickup, and I ran a 670 Truck Avenger at first on it. It ran fine, but I got a good deal on a 570 Street Avenger and used it on the truck, moving the 670 to a big block (mild). The 570 did the job fine for years, then I sold it to a customer for a 289 Mercury Comet I built and put a 625 Street Demon with the TQ-like plastic bowl on my truck. I like the Demon best of all, but I think with a 4spd in a light vehicle you'll be happy.
 
no it is fine , i ran an 850 tq on my 318 back in the day ran real well , that 670 should do well on a 318 . Street demons are also good
 
no it is fine , i ran an 850 tq on my 318 back in the day ran real well , that 670 should do well on a 318 . Street demons are also good
And with a manual trans, you will be able to tip in the secondaries much earlier than with a stock-stall auto, and in the process get some tire-frying fun.

I will disagree with the other opinions & suggest you swap the Holley for an Edel AVS2 carb.
I agree with most of what you say except OP is in Germany, so it's not like in the old days when you could buy a new carb for the price of a couple of tanks of gas.

i have bought some new parts for my stock 1969 Plymouth Barracuda, 318 small block with 4 speed manual.
The most-fun combination I have had, for a stock smogger-318engine in a 68 Barracuda, was a SMALL-PORT intake with a Thermoquad, which is a spreadbore Air-valve Secondary carb; and with some rear gears to make a starter gear in the range of 9.5/11 to 1..If I had it to do again, I might choose, a small mechanical secondary style of carb. But IDK, I love that TQ roar.

But that does not mean that the induction combo you have purchased will be significantly less fun. You just gotta tune it up real sharp. And not having had the small-port/small-carb combo, you will never know what you, IMO, are missing.

I assume you already have headers and dual exhaust, cuz the duals at least, shoulddabin your first investment.
I do not believe there is any such thing as too big a pipe size; With headers, mine was absolutely fine with full-length dual 3s; but I'm sure that is serious overkill........ I already had the pipes for my 360,lol.
 
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