I replaced my original Amals in 1979 the slides were so worn, but 13 years of no troubles with the replacement Amals I went down the PWK road with Jim's jets for my motor but 6 months ago I gone back to my old Amals with a rebuild, new jets and needle etc and unblocked the left Amal pilot jet, the bike is running the best it has ever been, I still have the same plastic floats, have never looked at the float level and the slides have no wear in them even after all the years they been on the Norton and lots of miles on them, don't know why I ever went down the road of different carbs, but I came back to my senses and the Norton runs so much better with the old Amals, but I do replace the jets and needle every couple of years depends on how many miles I clock up. But I have never had any problems with float level or flow except for the dreaded pilot jet blockage, but that was only once in 47+ years.
Ashley