I run my carbs locked together. I tune them as twins, what one gets the other gets. Just a pair of 1404 Edelbrock (not Holley) for my dual quad (NON AVS version). I will take a photo of my Edelbrock Uni-Syn Carb Balancing instrument #4025. I attached it to an aluminum carb hat cover and made sure both carbs were tuned the same. Works perfectly. I will check on the metering rods and jets questions. I had to hunt through a bunch of engine combinations and found information Edelbrock did on running a 350ci small block (close to a 348ci wise) that had two 1404's strapped to it. I have the jet/rod numbers in my shop. I'll get those up here with a photo of my balancing instrument.