I know when I drop over the hallway to the XK list for a quick coffee, there seems to be a few complaints that buying replacement rear leaf spring results in none [ or not enough suspension movement
I also recall a friend in UK who had new spring leaves on an SS 100 and the car sat too high.
The problem is metrification,
Spring steel for car leaves are a standardised metric size 6mm. The original springs had d a variety of thicknesses and the main leaves [ the ones that wear in the trunnions] on an SS100 are 3/16".
The spring works might say they can compensate , or more often say nothing . However , today i think have solved it . I went to the spring works and bought 4 lengths of untempered 6mm spring steel { which is flat]
I took it to a local grinder who grinds wet [ under flowing water] Important in that we don’t want the material getting hot and affecting the temper.
While they were at it they also ground the sides back to the original width because as supplied it’s slightly wider, the metric ‘equivalent’. They need to be correct to have the front U bolts fit and likewise in the trunnion housings. The good news was that all this was only AU$ 100 cash [ the great motivator]
Now off to the spring works to get them made into spring leaves.
And the ground finish , when assembled with grease should not have the friction from leaves sliding against one another , so smoother ride . The originals were listed as ‘lead coated’, presumably for similar reasons.