What is the vehicle? What does it weigh, what rear end gears? What trans? Where do you live, what is the ambient temp while you are driving?

If engine temp is too cool it will bog, unless tuned to run at that cool temp. Is the heat crossover in the intake clear and not blocked by a gasket? If you have not even checked the outboard springs yet you are missing important info. Know the basics first, then get fancy.

Why not offset linkage? THINK about it, WHAT does that linkage do? It closes two end carbs, so when your foot says to close them, it needs to happen right now. The linkage does not open the carbs.

WHY do you want offset linkage, what is the gain?