Not sure if this is the right sub forum since this is a street car but Im having some issues with the dual edelbrock AVS carbs on my 500" hemi .The problem is sputtering when transitioning from idle (while cruising down the road) to light throttle.I had a light sputter off idle under load with 52/58 rods,tried some 57/68 and it was much too lean,and just tried some 52/62 rods today and still a big stumble as soon as i lightly squeeze the throttle,if i hammer it past the dead spot it seems fine.the reason i have been trying some leaner rods is it seems to be running too fat especially at idle but yet its too lean coming off idle !Any suggestions? it seems that swapping rods may not fix this.

Try stiffer springs first, you want the mains coming in a little sooner...get it right and the signal will be stronger and the seconfdaries will come in stronger.

With AVS's it's usually the springs that make the biggest difference unless your calibration is WAYY LEAN or WAYY FAT.

Are you running staggered (rear primary opens sooner than the front....OEM hemi style) linkage or 1 to 1? If staggered sometimes a larger shooter can help a tad.

Best way to sort it out is to get the car on a chassis dyno with a wide band up the tail pipe. Otherwise you'll spend all summer fooling around changing jets and rods.

The two step rod design is really nice because it allows you to dial in the mid-range without changing the WOT mixture.

If you think you are too rich at cruise but fine at WOT then you should go with a rod that is leaner on the first step and leave the second step alone. The second step doesn't come into play until the vacuum drops and the spring lifts the rod.

Do you have a vaccuum gauge in the car? You really should know when the rods are kicking in before you start changing them.

If it is too rich at idle then you need to fix that before anything else. The idle mixture will affect all of the other settings. If your idle is too rich then all of your other calibrations will also be off.

I will add that 58/52 rods are just about the richest rods in the entire line up. Are those the original rods? Which carbs are these? If you have anything other than the dual quad carbs then you might want to start off by putting the dual carb calibration into your carbs and going from there.

I've run dual quad Edelbrock carbs before right out of the box and they work great. They have carbs that are calibrated for dual quad use. The dual quad carbs don't have 58/52 rods in them that is for sure!