All the Weber carbs. we sell are the genuine article – we don’t sell any that are made in China or the US. We get phone calls every week from people who have bought the Chinese copies (sometimes sold as genuine Weber carbs) who have problems getting them to run. We can re-jet the carbs. to your specification normally at no extra cost. Please contact us before ordering to discuss requirements. If you need different venturis there may be a small charge to change these.