[slugish]

[QUOTE=piecesparts;2397436]

Originally Posted by slugish

OK, so it is a slightly bored motor that has a little cam to it, I had a 2200 stall converter on my 383/700R4 combo and was experiencing the rough idle circuit mess at a stop. It cleared up when I went to neutral. I stepped up to a 2400 stall and solved many of my problems. I would support some of the thinking that a double pumper is more of a higher RPM carb and if that appears to be the issue then you need to go to a different design. As you can see, EVERYONE has an opinion which is best for an engine. Some like Quadrajets, some like Holleys, others like Edeldbrocks. I am presently running an Edelbrock AVS carb--mostly due to the CFM rating of that carb and the fact that the intake is made for a square bore carb. If your intake is designed for a spreadbore, then look for a Quad, it would be better than trying to modify with an adapter and loose volumetric efficiency. I have worked on the Quadrajets in my past--haven't lately and they work great--once adjusted and set. I had some bad early experiences with Holleys, but they supported anything that I did in those days just the ruptured power valves. You will read a lot of trashing on the Edelbrocks, but for the money they work really well--if you spend a little time adjusting them.

Before I purchased my carbs, I talked to the reps at Holley and the reps at Edelbrock (I do like going on the Hot Rod Power Tours--just for that reason). Of course, they all push their own items, but they also quote a lot of info and most say the same thing. For a truck being driven on the street, you want to keep the airflow velocity up, so that it will not lag behind the motor. That means running a slightly smaller CFM carb. The heavier weighted vehicle will respond better to that thought process. (Example run a 625 or 650 CFM carb rather than a 750 CFM and the response will be better) A lighter weight car, such as a Camaro will work better with the 750 CFM carb. The Holley people support a vacuum secondary actuated carb is better, they say the feathering of the secondaries is smoother. I have found that the Edelbrocks that I have run work just as well without the vacuum actuated diaphragm design. (I have adjusted my springs, needles and jets to what I like)

Did you know that the Edelbrock AFB design carb and the Carter AFB design carb is the EXACT SAME carb. (both carbs are made by Magnetti-Marelli) The parts are interchangeable---even if the parts distributors say that they aren't. I have a Carter in my basement that is full of Edelbrock parts (Edelbrock is cheaper than Carter on parts)

You still need to make sure that you are getting your carb adjusted to where the idle is in the idle circuit part (butterfly relationship to the venturi)and not in the transition area---gas smell and bad mileage is normal there. Where do you have your idle mixture screws set at? I set mine using a vacuum gauge instead of by ear, however both methods work . I am also going to ask, where do you have your intial timing set at? Maybe it is set to low.

If you think that your carb is leaking gas, try closing down on the idle mixture screws and see if it runs with them closed off. There is a possibility that it might with the gas leaking into the intake.

really appreciate your feed back . dont really understand how I can check idle in the idle circuit part vs. the transition area. Also dont know how to check idle with vacuum guage. thinlk my timing is at 36 degrees . Am going to track this weekend . wil let you know what happened. obviously im not a mechanic , but will run your ideas by mechanic friends . thanks again for your input.