If you have reproduction petcocks based on the original Norton design using BPT (British Pipe Thread) you will have no problem screwing this on. To fit the Norton Commando, we have improved "H" style fuel line assemblies with stainless fittings and steel junctions.
The fuel assembly is correct to original. Assembly was a little tight between the Amals, but I was axle to get it installed. Paid too much for these, there are better deals on the same U.K. Made assembly.