I am running Landsdowne internals and my forks don't clunk at all as well I fully up graded my front brake with a full Grimica brake system from RGM that was over 15+ years ago, one finger operation if I want too and the front brake on my Norton is as good as my modern front brakes that was on both my 2013 Thruxton (single front disc) and my 2016 Thruxton (twin front disc), but then I am not a heavy brake user and very rarely use my brakes while up in the tight twisties, but then my Norton is built for lightness, handling and performance up in the mountain ranges where I ride it hard, but I very rarely use my brakes hard while riding mostly for stopping lol.
Ashley