I have a carter carburetor with the number 384-9637S on it which iv found means its off a ford. This obviously makes since cause it came off a 351 windsor but I also found it "has provision for EGR" and i dont know what that means. My main question is what size metering rods should i put on it if its now on a 318

 

As for the size of the metering rods you need I have no idea, but EGR in itself means exhaust gas recirculation, so the provision on the carb is a hook up for your EGR system so it can "reburn" some exhaust gases and lower emissons, all it is is a emmissions control device