I have a blown 350, 5 lbs boost with 2 - 500 cfm Edelbrocks on it, can't remember why but the Edelbrock guy told me no to a progressive linkage on it, adjust both evenly and its been on the road since 2000 with no changes. One thing I might add is the Edelbrock tech when asked about chokes said, "man you have 2 500 carbs and you think you need less air & more fuel" and recommended against it, though I don't have any chokes the motor needs it, when its cold out at night she's running lean with the dense air and pops. Yes on the rejetting and rod changes, especially if you are not running progressive linkages. I know a guy running 2 Edelbrocks normally aspirated with progressive linkages and the motor is running leaner on a few cylinders and rich on others and not running right, I would say manifold selection is critical to keep from having that happen, I believe he was trying to do that on a single plane tunnel ram setup. Best of luck it will look cool. Matthyj