Mopar 318 Mixture

[Oakhouse410]

Hi there all
I would appreciate some advice please. I have a Bristol 410 with a Mopar 318 cu in. She has tubular exhaust manifolds but is as far as I can see otherwise standard. She isn't burning any oil and seems in good order. Recently I replaced the Carter AFB with a brand new Edelbrock 1406 Performer 600 cfm carburetor as the spindle had worn on the Carter. I have a Winterburn capacitative discharge iginition system fitted.
The ignition timing is about 15 BTDC with vacuum advance disconnected and 500rpm. This setting gives the maximum reading on my vacuum gauge. Mixture screws are out about 1 3/4 turns each. There is no bogging or hesitation. Very sooty exhaust and plugs. In an effort to improve the situation, I have tried changing the jets to Main 0.095 and Secondary 0.092. Metering rods are 075 x 047. Will changing the jets improve the mixture or will these settings be too lean? is there anything else that I should do. I normally drive the car gently at a maximum of around 65 mph without much fierce accelaration. Also, at what RPM does she start running on main and at what sort of RPM do the secondaries cut in?
Your advice appreciated
Thanks
Andrew

[Pete]

Hi there, first step is to set the timing at full advance, Vacuum off and plugged.

Aim for 34 degrees full advance and then see what initial timing you are left with....

[Adam]

I would focus on the metering rods and springs before changing jets (after setting the timing, as Pete said).

On my application (440 with mild cam), I had to use lighter springs to allow the reduced vacuum at idle to overcome them. The stock springs allowed the metering rods to 'step up' to the main circuit at idle, making it run very rich.

But it could be lots of things. Best bet is to return to stock configuration, and work through the Edelbrock guide: https://www.edelbrock.com/media/wysiwyg ... manual.pdf