Can I just confirm that the fuel line ID is 1/4 inch for a standard 998cc 76 Clubman?

I've been searching the forum and have read some posts that say it is 1/4inch and others say 5/16. Does the 1275 engine use the larger sized pipe?

Thanks in advance.

Carby cars from factory ran 1/4" lines, the 5/16 dual lines were for the efi cars, though lots of people upgrade to that size when they run more powerful engines.