A new carburetor can dramatically increase the overall horsepower made by your 350. The carburetor is located on top of your intake and it delivers the fuel and air to the intake manifold. A four barrel carb is one of the most popular upgrades as it is capable of delivering much more high RPM horse power than a stock two barrel. It is a good idea to stick to big brands such as Holley and Edelbrock, and these products are the carburetor of choice for most racers. A good tip to find the correct 4 barrel carb is to get one with the proper CFM for your engine. Multiply engine displacement (350ci) by the max RPM you will be running. 5,500 RPMs is a good place to start. 350 x 5500 = 1925000. Then divide the product by 3,456. 1,925,000 / 3,456 = 557. So you would need at least a 557 CFM carb. You will want to go a little bit higher of course, so a 650 CFM carb would work well in this application.