FST Carburetors RT Plus carburetor with vacuum secondary and manual choke combine the durability of a pressure forged carburetor with the performance of pressure forged metering blocks and bases. These carburetors are ideal for the weekend warrior who wants the road reliability during the week, and the track performance by the weekend. The RT PLUS Series carburetors come with black electroplated pressure forged metering blocks and bases for an aggressive appearance. Similar to high end carburetors in the performance aftermarket, these carburetors offer the full array of options and tune-ability.