I think the info is correct - it's consistent with other sources.
The uprated/shorter springs that are available through Canley (and others) are all advertised at 330. If I compare my new springs with the original 13/60 springs (203lb) they do not feel any harder at all.......when I do my incredibly reliable bounce test.
Given that so little is on offer, I shall road test the ones that I have and then decide what to do. I may have to cut some standards. I'm sure I will find a buyer for the "uprated" pair - once I have returned them to a salable colour.
I accept that my approach isn't particularly scientific, but I will enjoy experimenting. There are plenty of threads such as this one -
http://club.triumph.org.uk/cgi-bin/f...?m-1294420747/
in which members have changed to 330 (or even 440!) and say that there is not much difference! Very odd.