Stock 440, stock cam, with headers on my Chally 4-speed.
The problem is 1) idles too rich and makes me sick to my stomach and 2) stumble/bog when accelerating at lower RPM, occasionally will backfire thru the carb.

I'm overwhelmed with all the posts on Edelbrock carbs and not sure where to start. Yes, I prefer Carter to Holley.

I'm pretty sure I got the timing right and have tried real hard to adjust the idle screws with vacuum gauge for max vacuum. Vacuum advance connected to constant vacuum. Vacuum about 19 at idle.

The accelerator pump rod is in the hole closest to the carb.
Should I start with rods or springs?

floats are correct I am assuming (level dimention/not waterlogged/linkage free). might need new needles/seats (available seperately & are cheap). fuel PSI might be too high (common with eddys). what is your initial? EDIT what is the vacuum? baseline rods/jets in there I am assuming. Almost forgot the most important one: rods being held down steady at idle?

I'm going to almost totally disagree with RR on this one.
This is where to start, and I'm very serious. Don't worry about those other Edelbrock threads. Some may be relevant, most won't be.

1. A notebook if you haven't already. Because it is too much detail to keep track of in your head.
This I'm pretty sure I got the timing right isn't very helpful to the rest of us. Being "pretty sure" and "right" is open to too much guessing - What some people think is right, others think is wrong. Post the numbers. What will work best and what your goals are will depend on mods (in your case apparently none except carb) and whether you're going for stock timing setup with emmissions or hot rodded to some degree (considering its a stock engine).

1a. This occasionally will backfire thru the carb is timing related. It's firing early, before the intake valve closes. Write down the timing at rpm from idle until it stops increasing. (Plug the vacuum advance line for this. Golf tee works well.)

2. Download the Edelbrock Performer and Thunder Series Carb Owners Manual.
a. Notice on page 2 that the idle fuel is controlled by 2 restrictions, 2 airbleeds, and idle mix screws. ( Not the rods and main jet.)
b. Robert is correct that fuel level is important to be set correctly because the weight of the fuel in the bowl adds to the atmospheric pressure.
c. Chrysler's Master Technician series has some decent booklets and filmstrips on how carbs works (and they tend to focus more on the Carter designs). Check 'em out. Look under 1966 and '69.
http://www.imperialclub.org/Repair/Lit/Master/index.htm
http://www.imperialclub.org/Repair/Lit/Films/index.html

3. Vacuum advance connected to constant vacuum. Well... whether this is best way to do it will depend on your goals.
Stock factory setup will require everything to be like factory at the starting point. That means idle stop solenoid if applicable, factory initial timing, and ported or manifold vacuum - whichever the factory used.

But if you are going for a more typical hot rodded set up, no idle stop solenoid, no egr, then whether ported or vacuum source is better will depend on the initial idle timing you use as a base. Your cam should pull good vacuum at idle, 12-15 in Hg. That's more than most hot rod or race cams, so your using manifold vacuum will add significant timing at idle. Having lots of initial mechanical plus full vacuum advance at idle can result in will run best with a very lean idle mix, but likely too lean to have good power when you let the clutch out. It's a balancing act to find what the engine wants.

Start with timing as discussed and then idle mix. If there's any issues with the idle and low speed drivability that can't be adjusted with the mix screws and throttle position, then look at the fixed restrictions. You'll have to the measure the restriction sizes using shanks of small drill bits (or gages if you have access to them).

Once you have idle and low speed driveability, then work mid speed and high speed cruise. After that, tune the accelerator pump to cover and work on high speed WOT tuning. The chart in the Edelbrock book will be a big help on the high speed (interstate highway) and WOT tuning.

Thanks much guys! I will check timing and get back with you.

Backfiring is gone. My best performing timing is about 16 at idle, 30 at idle with canister connected to constant vacuum port on the carb, and about 50 total all in. (My timing tape only goes from 15 to 40).

Vacuum is about 18" at idle. 180 thermostat. CH14YC plugs.

If that seems OK to you, what would be your first step with the Edelbrock 1413 800 cfm carb, keeping in mind the stock cam. It appears to have silver 8" vacuum step-up springs in it, not orange (5" vacuum) springs.

best would be an A/F ratio bung welded into an ex pipe for an LM1 or 2 or wallace racing has some good plug reading pics. for the power circuit I would run a vac gauge into the interior so you can see what # you have at any flat spots & to just get a baseline on your numbers at different driving conditions. EDIT with the stock cam you might be pretty close on main metering, not sure if the 1413 is jetted rich out of the box but likely it is. then pick the right springs by working with your vac gauge reading numbers. MORE EDIT for a stumble confirm that the AP tip in is immediate & of enough duration & that float level is correct then richen rods/jets as needed.

Update: I narrowed the problem to the idle circuit in the Edelbrock 1413. I could turn both idle screws clockwise all the way shut and the engine would speed up.
I took the top of the carb off and cleaned out the idle bleeds, which were clogged. The discharge nozzles were also partly clogged. I ensured the float level was 7/16". I put it back together and then I ran the car and sprayed lots of carb cleaner in the idle screw holes with the engine running. The stumble is gone and it runs better, HOWEVER...it still can idle with both idle mixture screws closed. Now I get the highest idle vacuum with the drivers side idle screw only 1/4 turn out, and the passengers side about a 1/2 turn out.
That's still nowhere near the 1 1/2 turns it should be, so...I still have an idle circuit problem somewhere.
What should be my next steps?

just me I would take it apart & soak it in the soup (modern stuff ain't as wicked as the old formulas were) then rinse/clean it with solvent then clean with shop air then blast all passages with brake kleen the air blast again. & a good filter ahead of it. if you have to run E10 & you get another kit for it you might see if there are alcohol resistant seals/gaskets available. "the carb shop" in Eldon Missouri (google it) might have info as he is a top notch carb man (very expensive tho).

should be? really?
Robert is probably right about the additional varnish and gunk.
If so, that is important to clean up. That's the heavy end of fuel, not specifically the ethanol, but it is worse in today's street fuel than was before reformulation.

But to tune a non-stock carb you need to understand it better. So go back to my post above for what you should do next. As mentioned it's also very important to get the timing correct. Then its easier to get the correct throttle position and idle rpm. Once the throttle position is correct the mixture screws can be used to fine tune the idle mix.

Frankly, I find it hard to believe a '70 up 440 factory timing curve started with 30 degrees. But show me wrong, then I'll believe you've got a good baseline to start tweaking. Your engine is stock, so factory is a good starting baseline.

Maybe this will help:
Initial timing (aka Base Timing). Usually set at an rpm below the rpm where the mechanical advance begins.
Mechanical advance: The timing added. Maximum mechanical advance is built into the distributor. For example a slot plate stamped 11 (distributor degrees) will allow roughly 22 degrees.
Total Timing: Almost always refers to Initial+maximum Mechanical Advance.
However, the factory engineers were sometimes more clever than hot rodders and racers appreciated. Some distributors have a very heavy secondary spring so the weights don't hit the end of the slot until 5000 rpm or higher. So, just pick a reasonably high rpm, like 2800 or 3000 rpm and just be consistant in using it for the "total timing".
example: Set the initial timing at 600 rpm to 10 degrees BTDC. Using a distributor with a 22 degree advance, expect Total to be 10+22 = 32 degrees. The rpm it will hit 32* or even 30* will depend on the springs.

Vacuum advance: Usually not used when setting initial. On an original engine, you'll find some use manifold source and others a timed (aka ported) source depending on year and engine. The ported vacuum is sourced so it provides zero vacuum at idle. Otherwise it is the same as manifold vacuum.

Thanks Mattax! Everything you wrote is very helpful and crystal clear.
My carb is an Edelbrock, not a vintage Carter, but I don't believe the carb has been modified. True, it's non-stock.
I should have mentioned...since my first post I have switched from manifold to ported for the vacuum advance.
So I have 15-16 degrees BTDC initial. The distributor is a "4-seconds flat" unit that he specifically did the mechanical and vacuum advance for a 440 with iron heads, stock cam, 4-speed and 3.23 gears. If I plug in the vacuum advance to manifold vacuum it jumps from 15-16 to 30 BTDC.
I put it back to ported vacuum.
According to all the Edelbrock videos I have seen, a good starting point for mixture screws is 1 1/2 turns, not a 1/4 turn. That is what is bothering me. And yes, if the timing is not right and the throttle position is not right then the idle mixture is moot.

It's just a starting point and since the Eddy is a universal carb, its very possible the trim on your engine will be something other than 1 1/2 turns.

The Edlebrock circuits are very similar to the Carters. That's why I suggested the Chrysler Master Tech stuff. In fact the basic concepts are really similar to the Holley, Motorcrafts, Webber etc; they really only differ a little in how they carry out.

Don (FBO) has his own ideas on ignition curves. Since you got it, try to work with it. I like to know what is going on. If you do too, then measure out the timing advance at rpms until it stops. Then measure the vacuum advance using a mityvac.

My guess from looking at the late '60s factory curves is that 16* is plenty for a stock 440 at idle. But you could experiment.
But what is idle rpm? 600? 800?
Here's the thing, if the idle rpm is a bit high then its possible the throttle blades are open more than ideal. That would mean more fuel from the transfer ports = another possible explanation for the engine only needing a little bit of fuel from the idle ports at idle.

OK, the carb is all sorted out. Plus, I just to be sure I went out and bought a Holley...and that runs a bit better than the Edelbrock. No stumbling, no hesitation.
It just feels flat from 3500rpm on up. So now I'm back to the timing. 16 degrees initial and 30 total with vacuum advance disconnected. I guess the total is a bit on the low side.
If I advance the initial beyond 16, it feels like I begin to lose torque.This is an FBO distributor.
I've put in a question to Don, but also would like to hear thoughts from you all also. thnx.

It ain't timing. vac leak? EDIT & when you say the can is disconnected you mean the can ain't being used at all OR that you are checking (initial+mech) total with it disconnected/plugged (which is proper procedure). MORE EDIT I missed that the hesitation is gone. "flat" as in just a lack of power? yes you need more timing and when (RPM) is it all in at? may need mixture and or fuel delivery volume checking. is this part throttle or WOT or both?

Hesitation is gone after cleaning the Edelbrock carb...and when using the Holley carb.

Yes, what I meant to say is, I'm checking the initial and total with the vacuum advance disconnected. 16 initial, and 30 total mech in.

I'm not sure what RPM the total mechanical is in since I'm under the hood.

I do use the vacuum advance when driving... and I connect it to ported.

So now my main problem is, lack of power at mid-to higher RPM.

Although torque at launch isn't that impressive either. I had a 318 2bbl that felt much stronger than this 440.

Can't be guessing this stuff. Get a remote tach, a buddy, or use a screwdriver on the throttle stop screw.

edit: How are you measuring the 30 degrees?
Timing tape, or dial back or addition?
First two are OK. The last can not be relied upon until verified by the first two.

Timing tape

Is the long block healthy? you might check cranking compression and leakdown. (basics never hurt). vac leak/mixture in ballpark/free flowing ex/unrestricted air cleaner. any changes or adjustments immediately preceding this? I would see what RPM the adv is all in & I would want 36 total for a good ballpark. You may have already posted on some of this. assuming the TDC is good, 2&1/4" CW on the dampener from the slit is 35.5 degrees.

Check your voltage at coil positive post to ensure that your ignition coil is getting proper voltage. Should be in the neighborhood of 8 to 9 volts after running thru ballast resistor while engine running. If not at this voltage, check wiring all the way back to ignition switch,,,,,,or jump from positive battery post to coil positive for a short time drive to determine if your issues are resolved.

Wonder where your carb butterflies are at when at idle. The fact that screwing mixture screws all the way in makes no difference suggests a vacuum leak or you are idling in the transition zone. Although high idle vacuum reading does tend to contradict that.

Hopefully vibration dampener in good order and timing mark has not shifted on it. Backfiring and poor performance are suggestions of retarded timing,,,or severely lean mixture. How do your spark plugs look?

Assuming spark plug wiring is correct and no bad or burned thru wires. Run engine in the dark with hood up.

Throttle screws all the way in?
I thought that was resolved.


Heh. You actually wrote that in an earlier post and I forgot. Sorry. FWIW On a stock diameter damper, I liked the Mopar Performance tape. It goes all the way around, and is black with white lettering making it easy to read.

I assume you understood what I meant when I wrote 'use a screw driver'. Its a small PIA but sometimes easier than finding a good helper. Depending on the air cleaner base, you might have to use a short screw driver or check the timing with the air cleaner off.
- To make it easier, set your notebook or clip board up with the Timing and RPM columns before hand.
- Get the low rpm when the engine is warmed up and reduce the engine speed to the lowest rpm it will run well enough you can read timing. Then turn the idle stop screw in a little and write down the rpm and timing. Repeat until the timing stops advancing.

This important because tuning an aftermarket carb requires the timing curve has to be pretty close to what the engine wants. Timing and fuel ratio go hand in glove because the a leaner less dense mixture in the cylinder will burn slower.

I suggested looking up the stock timing specs because that's a baseline reference we know works. If the engine in your car originally had emmissions controls that are now removed, then an earlier timing curve may be a better reference.

Another reference point are the Direct Connection recommendations. Total mechanical for a B or RB motor:
38 degrees at 2600 to 2800 rpm for production and stage I-V iron heads.
(Instruction Sheet DCF-194, Mopar Performance Electronic Ignition Kit. p6)

My guesses are that
a) sluggish mid to high rpm is due to insufficient timing above 3000 rpm.
b) the change you feel with more the 16 degrees at idle may be due to the strong vacuum signal from the stock cam. Try driving it without the vacuum advance (cap the ported vac or golf tee in the hose) and see if it feels different.

As the timing gets closer to what the engine wants, the carb can be tuned to match. It will likely take a few iterations.

Getting the idle and low rpm cruising tuned is the most difficult part. Doing it first is the best way to approach tuning because the 'idle circuit' takes fuel from the main circuit and also provides an airbleed to the main when the throttles open.

A few questions:
What is the Holley List number?
Is the intake stock or aftermarket?
Were there any emmissions systems besides PCV?