Question on adjusting dual quad carbs.

You need a Edelbrock unisync and some kind of carb cover to make a tool to make sure the carbs are timed up correctly.

Amazon.com

And one of these:Amazon.com

You have to make the hole in the carb cover bigger and then glue the unisync to the cover.

Get the engine running and disconnect the linkage from one carb. You can’t have the two carbs hooked together by the linkage.

Get the idle speed where you want it.

Pick a carb (I usually set the front carb but either one works) and set the unisync on the carb. You’ll feel the hat get sucked down.

Read the manometer on the unisync. I usually set the gauge in the middle. There is a built in valve on the unisync that you can open and close to get the manometer centered.

Once you get a clean reading on the manometer pull it off and set it on the other carb and read the manometer.

If the readings don’t match, and unless you have the Midas touch they won’t match then adjust the second carb to read the same as the first carb.

And you do that by adjusting the curb idle screw.

It’s very difficult to get both carbs equally open or a better way to say it is get both carbs flowing the same air at idle regardless of where the curb idle screws are at.