sidedraft Weber vs. downdraft Weber

[amgba]

I guess the real difference is in how much you want to spend. While a sidedraft Weber will outperform a downdraft Weber, the differences are small unless you have properly prepared the engine to take advantage of the sidedraft carb. By properly prepared, engine needs to be in top shape and the sidedraft needs to be custom setup and tuned for your engine. (The same really applies to any carb you choose to use.) The sidedraft is expensive and difficult to get tuned properly - and it will consume more gas. If you car is not going to be used hard with high engine RPMs, then you probably will not really see the full potential benefit of the sidedraft Webers. In my opinion, you should upgrade the engine's condition before spending on sidedraft carbs.
Art Isaacs